penna-
Don't really know how "collectible" these are, rare, yes!
Also, with this list of things that need attention-
Has bypass switch for fuel pump. Guess something in wiring harness, haven't tried to fix.
Brakes could use adjusting, Tires are cracked but hold air. Belts have cracks but work.
mower deck has a few small holes, wheel repairs needed. Blades need sharpened!...you may want to lower your price, as $850 can buy you a much newer rider these days.
But, then again, I don't know your market either.
Good luck with the sale!
Rattosh51
YT6800