I couldn't get your link to work but here are the sure seals from this site. They only fit 9N and 2N and your serial number leads me to believe you have an 8N.
Ford 9N Rear Axle Sure-Seals Additional Information:
Fits 9N, 2N. 1 pair. No need to split collar and replace old outer axle seal. Sure-seal fits over top of sweat collar.
Part Number SS92