Hypothetical scenarios suggested so far in this thread:
1. Alan Fords theory: The curtain rods were "given" to Oswald with "instructions" by a conspirator, and Oswald followed those instructions exactly. Oswald did not get upset enough by Marina to completely just walk out that night of Thursday, but stayed till Friday morning and completed his task. Oswald took the package, was seen by at least BW Frazier, and was seen taking the package thru either the actual back door or the back door of the Annex part of TSBD. Afterwards, conspirators would remove the package before the shooting starts.
2. Walt Cakebread theory: Oswald may have placed the curtain rods OUTSIDE of the TSBD, either somewhere near the actual back door or by the annex building back door, just BEFORE opening the door.
3. Zeon Masons theory: Oswald took the curtain rod package he found in Mrs Paine garage that night and decided just to take it without permission, since he was already upset with not having reconciled his separation with Marina. Oswald went thru the back door of the ANNEX building, still carrying this package, which BRW observed as "going in the back door" of the TSBD. Oswald placed his package in some container inside the Annex building area, in the 30 seconds of time he had before BRW would reach either annex back door or the TSBD back door.
The problem for Alans theory , imo, is that its very convoluted and complex and just one little slip up by Oswald and the whole plan falls apart, as far as trying to pre event set Oswald up as having carried in a rifle in a package. Or what other reason would there have been to have Oswald be seen carrying a package? Also, if the reason for the March 15th document is because a package WAS found in TSBD albeit late and unexpected, then either the conspirators FAILED to remove the package or ANOTHER package was placed sometime later to be found, just as a gag?
Walts theory, actually might explain Oswald not being able to get his curtain rod package post event, if Oswald did in fact exit TSBD via roll up door on ground floor right beside the west elevator. Thus, Oswald exited into the Annex building 1st, saw thru the annex back door window, 1 or 2 plainsclothes officers, as DPD officer Barnett described may have been there watching that exit. Oswald likely would have then gone to the WEST side exit door of the Annex building, thru which he might have escaped, as its its unclear if that west side door was yet being guarded.
However, BW Fraziers statement is that he saw Oswald go INTO TSBD with the package, so that would suggest going thru either the actual back door, or the back door of the Annex building.
Another alternative, a synthesis of the above 3 theories:
Oswald was actually PAID MONEY, to carry some additional smaller package INSIDE of this larger curtain rod package. That might explain Oswald willing to complete an "instructed" task even though he had been fooled by Mrs Paine to believe Marina wanted to reconcile thus compelling Oswald to return with BW Frazier on Thursday instead of his usual Friday ride.
Oswald therefore took the package, and left some of the money he was paid, approx $150 at least, for Marina. He took the package at least as far into TSBD as the Annex building. The conspirators who might not have actually been setting up Oswald as a shooter, as Alan Ford has proposed, took that valuable part of the package and left the actual curtain rods there in that container where Oswald had hidden the package. That might explain finding a curtain rod package some 3 months later, by accidental discovery.
If Alan's theory is correct, there are TWO , possibly even THREE sets of conspirators, one set whom really WERE trying to set up Oswald as a shooter, one set whom just wanted Oswald to be a "Mule", to carry in some expensive, substance like cocaine or heroin, and the 3rd set, the post event collusion of LBJ, DPD and FBI to simply make Oswald the scapegoat and avoid any further unpleasant investigation that might expose other corruption.