i have a few D20 t-cases if you are interested in one of them.... $50 bucks but i dont think i have a spare shifter for it....
in the semi near future i'll also have a t-15 3 speed trans from my cj6...but thats not out yet....and might not be the best bet for your project buggy thingy (i assume thats why you are asking)
I have a line on a pair of D30 and 35 axles....but some parts are missing....i'll PM you the link for that after this..
Keep dream'n on the seats

but I am keeping my eyes out for more at the same place when i pass by it...they always have something good there, havent seen any more seats yet though.