Stern propshaft housing extension added and waiting to be sanded and neatened up, and yes, the hull halves have been joined up too, at last:
I flattened the kit's original stern and butt-joined an extension made from a scrap section of the sprue from the kit, and then sculpted filler over it, it might take a few goes with filler to get this to blend correctly, but it's reasonably close already with this first covering, so that's a bonus.
This is based on the best guess from several (conflicting) blueprint drawings kicking about on the 'net and some photographs probably taken by a dockyard worker with a camera up his jumper, needless to say, there aren't exactly tons of pictures of top secret Soviet/Russian submarine scews, although once again, Wayne Frey's book comes up trumps with one or two. Also visible on this shot (just) is the join where the bottom fin is added, although the fin is edge-on in this picture, this needs sorting out too. The trailing edge of the fins will need thinning out a bit to come to a sharper edge.
Chock