Here's a PDF of the National lip seal catalog. I use it pretty frequently to match up dimensions on seals of various types. The shaft sizes of PTO's start around page 55 or so. If possible, try to find a double lip seal, which has a dust barrier outboard of the lip that actually does the sealing. They last a lot longer in hostile environments like where a PTO lives. Good luck!
Jerry

https://www.timken.com/pdf/7707_National%20Indust%20Seals%20Catalog.pdf


"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!