A QL should have came with a seat on it with some lines impressed and a mid back. I'm not sure they make a true original replacement, but a 6 pad is close. (Which is still available.) But honestly, unless you just absolutely want an "original" seat, a replacement seat is fine. Not like it affects the value of the machine any. You'll likely spend as much getting it re-upholstered as you will replacing it.
Check out this thread:
http://www.onlycubcadets.net/forum/s...highlight=seat
I am no help on re-upholstering the original