my suspicion IF Oswald is out there somewhere, that Oswald is in the area behind Lovelady but just LEFT of Buell W. Frazier.
In effect, Oswald came out behind everyone, and positions himself in the space between Prayerblob and Buell W Frazier and its THIS space which had to be darkened out.
Your point about PrayerPerson
not being blacked out of
Wiegman is well taken, Mr Mason.

As for Mr Oswald's precise whereabouts in that entrance, we thankfully don't need to speculate:

The first Wiegman frames show Mr Oswald at Mr Lovelady's left (i.e. east!) shoulder, after which his head moves west------------

-----------and Altgens shows a tiny portion of Mr Oswald peeking out behind Mr Lovelady's left:

Altgens therefore must have been taken
just before those first Wiegman frames. Certainly not after them, as Mr Lovelady has stepped down by then.
This is not a fire drill, folks, this really is the official story burning down to the ground! 