Ya nailed that OMS model, nice work!
I had a bit more of a go at editing textures (not trying to step on your toes or anything Pak, just something to do while waiting for the hype train to pull into station). The Buran nose has a scale of 1.0, 1.1, 1.0 in the cfg to give it a bit of a stretch in length, not sure if it's the right thing to do, but I thought it made it look a bit less stubby, and more like the real Buran. Added a textureswitch module to the Mk3 cockpit and refined that texture some more. Removed the black tiled ares between the windows, squared up the window borders on the top of the cockpit, whitened the hatch border (Buran only has the black outline on the center circle) and removed the window in the hatch. The white areas also have some very faint tile outlines and less pronounced panel seams. Also tried to replicate the asymmetric tile pattern on the nose. I play with these in RSS/RO, so they're just to satisfy my own pedantic nature. I'll leave the textures here if anyone wants to make use of them (keep in mind the tiles line up best with that 110% scale in the Y-axis on the nosecone).
The Buran airframes with the nose docking ports were just a cheap way of throwing a few space tugs in orbit. They weren't really a variant of the Buran, but more of something to do with the leftover junk from the program. They were going to be reused test articles (similar to Enterprise and the other wooden space shuttles) with an OMS system slapped on and a cargobay full of bombs. They weren't meant to reenter, and were disposable. Having a nosecone like that beneath a heatshield sounds like a pretty sketchy proposition, but it would be neat.