Why would the Soviets/KGB withhold info on Oswald's Mexico City impersonator?

[Steve M. Galbraith]

Faking Oswald's presence in Mexico City would not have been necessary to frame him for the JFK assassination.  And risky if the Russians or Cubans had evidence to the contrary.  There were ample grounds for the fantasy conspirators to label him a political kook (if that was their intent) based on his defection to the USSR and ongoing nutty political involvement with Marxism following his return to the US.  There would have been no need to send Oswald or an Oswald double to Mexico City unless there was some intent to implicate Russia or Cuba into the plot as a pretext for war.  But what do the conspirators do according to our resident CTers?  The exact opposite to this undermining this explanation.  They immediately place all the blame on Oswald and cover up the involvement of anyone else including Russia or Cuba. 

The Cubans and/or Russians may have had grounds to be suspicious that Oswald was working for the CIA.  It's possible that they were understandably concerned following the assassination that his presence was part of a plot to start a war in Cuba.  For that reason, they might not have been entirely forthcoming about what Oswald told them.  Did he admit or imply his involvement in the Walker attempt to validate his credentials as a loyal Commie?  Or make some vow to do so?  It wouldn't surprise me.  Oswald's actions leading up to the Mexico City visit were directed at creating a resume of his credentials to impress the Cubans.  What better way to do that than admit or imply involvement in some risky act like assassinating a right winger like Walker?  The Cubans would have good reason not to admit that Oswald had told them he was willing to commit some violent act on behalf of the cause.  I think Oswald would have played every card with them and that was a strong one.

This is my point with the original question:  "And risky if the Russians or Cubans had evidence to the contrary."

Why impersonate him when the Soviets and/or Cubans could expose this impersonation? If the plan was to impersonate him to connect him to the Cubans and Soviets and then use this fake connection to blame them for the assassination (especially Castro) wouldn't the Cubans and Soviet expose this?

So why didn't they expose it? It seems obvious to me: they didn't because he wasn't impersonated. This was not a made up story by the three KGB agents to sell a book. They informed Moscow right after the assassination that they met Oswald. They didn't tell Moscow it was a fake, an impostor. If they had the Soviets would have clearly made that known. But again, they didn't. For more than 30 years they didn't.

Because it was Oswald. Or, if one insists, a damned good fake.

[Jon Banks]

This is my point with the original question:  "And risky if the Russians or Cubans had evidence to the contrary."

Why impersonate him when the Soviets and/or Cubans could expose this impersonation?

How would they have known that someone impersonated Oswald? And unlike the Soviet embassy, some Cuban officials from Mexico City were not sure if they were visited by the real Lee Harvey Oswald.

The phone call impersonation claim involving the Soviet embassy originates from the FBI and some CIA officers.

How would the Soviets have known that the person who called the Soviet embassy on September 28th, 1963 was impersonating Oswald?

So why didn't they expose it? It seems obvious to me: they didn't because he wasn't impersonated. .

You're applying circular logic to dismiss credible claims that Oswald was impersonated.

You don't want to believe Oswald was impersonated so you cite what the Soviets said while ignoring what the Cuban embassy officials said.

J Edgar Hoover, the translators of the phone calls to the embassies in Mexico City, Sylvia Duran, and some of the CIA officials from Mexico City have all given us information that strongly suggests that at least in the phone calls between September 28 and October 1, 1963, Oswald was being impersonated by someone.

We can't confirm the impersonation story because the audio tapes no longer exist. But the descriptions given by the translators of the phone calls plus Duran's claim that she wasn't with Oswald on September 28th suggest that someone impersonated him.   

[Steve M. Galbraith]

Depiction of Oswald (or an alleged impostor) meeting with KGB agents in Soviet Embassy in Moscow Mexico City (from Nechiporenko's book on the assassination). Nechiporenko includes an account where shortly after the assassination Cuban Consul Eusbio Azcue met with fellow KGB agent Pavel Yatskov and asked why the Soviets sent him "that schizo [Oswald] for a visa?" Yatskov replied that "How could I have sent him? I don't handle visas." Azcue expressed no doubt, as he would later, that the man was Oswald.

[Jon Banks]

Depiction of Oswald (or an alleged impostor) meeting with KGB agents in Soviet Embassy in Moscow (from Nechiporenk's book on the assassination). Nechiporenko includes an account where shortly after the assassination Cuban Consul Eusbio Azcue met with fellow KGB agent Pavel Yatskov and asked why the Soviets sent him "that schizo [Oswald] for a visa?" Yatskov replied that "How could I have sent him? I don't handle visas." Azcue expressed no doubt, as he would later, that the man was Oswald.

NY Times:

Eusebio Azcue Lopez, a former Cuban consul in Mexico City, told the tribunal that the person claiming to be Lee Harvey Oswald who visited him Sept. 27, 1963, to request a visa for Cuba was not the same person who appeared in films and photographs as the arrested assassin of Mr. Kennedy. The Warren Commission reported the C.I.A.'s evidence that Lee Harvey Oswald had visited the Cuban consulate on that day.

“In no way did the person I saw in film and photographs resemble the person who visited me,” said Mr. Anue, who has never before given evidence in public. “The person in the film was younger and with a pudgier face compared to the hard lines and older face of the person who requested the visa.”

A member of a so‐called Cuban Investigating Commission, Idalberto Guevara Quintana, who presented today's main charges against the C.I.A., said that there was a growing body of evidence suggesting efforts to link Cuba to the assassination even before it took place.

Mr. Guevara charged that, contrary to evidence presented to the Warren Con%mission, no one by the name of Lee Harvey Oswald belonged to the so‐called “Fair Play to Cuba” organization in the United States and that no affiliate of that group existed in New Orleans, where Mr. Oswald had allegedly been a militant.

He also said that, contrary to evidence presented by the C.I.A. to the Senate's Select Committee, the person who sought visa for Cuba in Mexico City never announced while in the consulate that he was planning to kill President Kennedy.

https://www.nytimes.com/1978/08/03/archives/cuba-says-cia-fabricated-evidence-on-kennedy.html