If you can search/seek original A1 (leather) design/kind/type rear axle/hub/wheel oil seals,
As they DON'T&WON'T leak,
BUT you have to &must 1st soak them overnight in light engine oil.
The problem with modern neoprene rubber lipped seals is that when they get a slight " nick" in the lip they lose lubrication then get hard &can &do leave wear on the axle shaft negating use of a aluminium "speedie sleeve".In our expereince whenever a customer complains about a leak it's because the NON-original seals have gone hard&the owner/or mechanic hasn't been able to source original or aftermarket leather lipped oil seals.The part numbers you need, require want is:FORD B7A1177B/B7A1177B1/C7UW1177D, NATIONAL 6939