Xerox 850 / 860 hardware differences

Out of interest, does anyone know how much hardware commonality there is between the Xerox 850 and 860? We've got an absolutely beautiful 860 at the museum, with all the trimmings documentation and software-wise. We've just been offered an unknown-working-status 850 main unit though, and I'm not sure what's best in terms of fate: a) Pass on it and offer it here in the hope that someone can use it [1], b) Pull boards, PSU, drives etc. as source of spares if they're transferrable to the 860, c) Just consign it to landfill [2]. [1] There's no keyboard, no display, and no printer. I'm not sure what chance someone would have of simulating those with modern hardware, even assuming that the main unit is working / can be made to work. [2] The drives are doubtless useful to *someone* for non-Xerox things I would have thought. It's in Welwyn, UK. Shouts of "I'm close to there and desperately need an 850 base unit to go with my 850 peripherals" will of course be gratefully received :-) I'd much rather a complete system be restored than a partial system be stripped for spares! [I don't actually know yet that the current owner's happily to release it to anyone other than the museum, though - but can find out if needed] cheers Jules