Steve,
I didn't need the seal, as I changed to the -2 ZF. Apparently, that seal is used with the -1 (-1 1/2) that has the steel adapter in the back of the crankshaft. It is used to seal the pilot bearing.
That seal has the same OD as the pilot bearing (ie the ID of the steel crankshaft adapter), and the ID or shaft size is...you guessed it...the same as the ZF input shaft snout. The seal measures ~.202" thick. Kind of hard to measure exactly, as the back side is a little rough. No Numbers.
I just looked on Wilkinson's website, and it shows that "seal" as two pieces...a cupped washer (bearing retainer) and a felt seal..hard to tell for sure without cutting into it. I guess that the felt was nicely polished after all those miles so that it looked like rawhide. Here's the link, #7 & 8.
http://www.panterasbywilkinson...s/catalog/ill9a.htmlSee you in Monterey!!!
John