Before the Forum was hacked there was a good discussion about Gorilla Lovelady person and famous plaid shirt. Did Billy Nolan Lovelady really had that plaid shirt, is he the person on Altgens 6... Many questions without answers.
In my modest, armchair research I have reached the conclusion that the person seen on Martin/Hughes films, wearing red plaid shirt, later seen in DPD office when LHO was brought in, I think that person was Roscoe White.
Here is the time line:
This person first seen in Bronson film

He is standing here, in this area, in Hughes film

Than I see him in Dorman film

Than in Zapruder walking towards TSBD

He is standing on TSBD steps smoking a cigarette, seen in Martin/Hughes films

Thank he is here in Beers photo

And at 2PM he is in DPD office


Here is Roscoe White and person known as Mark Lanes Lovelady

To me, Gorilla Lovelady is more like Roscoe White than BNL.
I am searching for more images of Gorilla Lovelady.