I went to Napa today to try and find a replacement input shaft seal since Toyota doesn't sell it separately. Napa didn't have a listing for it, but they sent me to a company that deals with bearings and power transmission components (
Industrial Solutions). They were able to match up the seal based on the ID/OD and thickness, since most Japanese auto manufacturers don't release all the data on the seals they use.
We came up with part number 18-32-7-DL, and it cost me all of $3.90 and tax. I'll swap this in to the second gear box with the blown input shaft seal, so I will have a second gear box ready to go (not sure where, but it'll be ready!)
I'll update the first post with some part numbers.