Tail Shaft Leak - was "Is this gasket available? A904 Extension Housing Snap Ring Cover"

I have never seen an access port back by the seal. That is about where they used to install a big counter weight to keep the back end from dancing. But you can see the mounting points for that , just forward a bit.
The access port for the rear bearing is way further towards the front. up closer to the speed-O housing.

Wait a sec, I just remembered that the very early 904s with the Tri-pot yoke, had a bearing back there somewhere. Hmmmmmmmmmm, IIRC that rear bearing was snap-ringed to the output shaft. So
IDK what you got there.
But what I do know, is that if the Extension-housing was designed for a slip yoke, the RearBushing is right above that strap. Yeah, so; I wanna see what's behind that door; maybe a grease fitting? IDK
Very curious, I am