Front wheel bearings are just the common Set3 and Set5 from most rear wheel drive GM large body cars ~1970's. There is nothing unique or exotic about them; they are probably the most sold wheel bearings in the world up to mid 1980's. The seal is just a #1940 (don't quote me on that # ), available at all McParts. Have the counterman look up a 1972 Impala, or such, and compare that seal to yours and I'd expect a match.

__________________
The Golden Rule

1984 300SD (bought new, sold it in 1988, bought it back 13 yrs. later)