Hi Im looking for a seat for my K100RS 1986 
the one on my bike has a sheepskin cover & has a big gap now I've take this cover off so looking for an original that i can get recovered or direct replacement if in good condition 
TIA

Not sure how much you want to spend or how far away you are looking, but I found several on eBay just by typing your year and model into the search bar.

Kbikeparts.com is also still showing a Corbin Dual Sport on his website for 1986 and later bikes. About half the price of a new Corbin. Not sure what your budget is though.

Do you mean a gap between the tank and the seat cause of the sheepskin cover, or like a tear in the seat cover. $50 gets this one, I've got a few other options, I'll probably be in Melbourne next week or two.