Input shaft seal (in the bearing retainer)

You guys are overthinking this. Find a REAL parts store, or a local bearing supply house. Either get the no.s of both seals involved, that is the seal for the shaft so you can look up the seal ID, and get the seal no. for the housing, so you can look up the OD.

OR, of course, just "mike" em, go to a supply house, and find a seal with those dimensions.