Plastic timing cover

I have a K2500 1997 454 Vortec engine in my Suburban, it has been sat for a couple of years and I am recommissioning it, however oil is now leaking from the front cover, I assume the seal has cracked, I thought I would just change the oil seal but have read that this is not possible and I will need to change the whole plastic timing cover, is this correct?

If it is correct where could I purchase the whole cover from, I'm in the United Kingdom so no Chevrolet dealers over here stock this sort of stuff, they just order it in. I often get bits from Rockauto but they only seam to sell the oil seal itself and as I'm unsure if it can be replaced I would rather not buy one only to find it's not going to fit.

I have read that a steel cover can be made to fit but again I'm unsure as it looks like my cover incorporates the timing crank sensor and the steel ones I have seen don't have provision for the sensor.

Any help would be much appreciated.

Degrease the front of the engine, verify that it's the front seal that's leaking. "I" would also verify PCV operation including the vent back to the air cleaner. Excess crankcase pressure can make a good seal leak.

NAPA sells front seals, "Speedi-Sleeve" damper seal groove repair kits, and a kit with the seal and the repair sleeve packaged together.

NAPA doesn't sell a compete front cover. I therefore assume that the seal is replaceable.

Seal = 23300, $17
Repair kit = 99233, $60
Seal and repair kit = 480233, $72