My transmission's input seal (facing the engine) was leaking all of last season. The way I determined it was ATF and not engine oil was the color of the oil in the bilge after a while. I cleaned everything and put a white oil pad under the bell housing and found a red drip, but that was after it was leaking pretty badly. I pulled the transmission, replaced the seal, and re-installed in about 3 hours. You can get the individual seal from skidim, but I got the whole seal kit because there were some other o-rings there I wanted to replace too, and figuring with 1400+ hours my transmission will need more attention again soon, so now I have all the parts.
1989 Bravura w/ 1998 GT-40 engine swap