Front oil seals

[PhilA]

Starting to rebuild my engine, and the only really quite important seal that I can't get here for love nor money is the front crank oilseal.

I can't find a part number for the seal, but I do have the part number for the front plate that the seal sits in. (7700598397)

The oilseal has the following dimensions:

Outside diameter 68.6mm
Inside diameter 49.9mm
Thickness- deep flat side to flat side 10.5mm

Anyone shed any light upon this elusive seal? A regular one won't seem to work as it has a lip at the back (inner) side to keep it in place.

--Phil