"I render music from Poland, backwards"?
Or is it something to do with taking shiny notation, and rubbing it with a filthy rag to render it dull and patinated?

I've seen dozens like this, the benches are simply to raise food up from the floor. Anybody who works in the maintenance and alteration of 16th to mid 19th century houses in Britain will have seen cellars almost identical to this.
Niches in the wall were for candles or lanterns, building style early to mid 1800s. In the area where I work, most of the older houses have cellars similar to this, raised slabs of stone for keeping meat, cheese, butter etc.
In some larger cellars you'll find a big stone slab table in the middle of the room. These muppets, no doubt, would say that shows it was a black-magic crypt where beautiful virgins were sacrificed....

I've been interested in these screw-drive machines for a few years now. Whilst there has been a lot of research and development work in Russia, leading to a number of very able vehicles, I've seen nothing to suggest any russian machine as early as this.

Unless anyone can point to clear evidence of one, I'd be inclined to believe that either one of these made its way to Russia, and spawned descendents, or that Russian engineers came up with the same idea, but rather later (german troops captured several screw-drive machines in the second world war).

Saddle and harness rack, definitely.