Sorry if its a bit late....
Looks like it's probably a standard size, 32x47xW in Nitrile NBR should do it (the link shows 7mm, 8mm or 10mm depth W). You can get either single lip designs or an additional "wiper" or dust lip which is usually the type used where the outside can be exposed to dirt/dust, so I'd suspect that'll be the type used, single lip referred to as R21 and double as R23.
https://www.bearingsrus.co.uk/sealing-p ... r_mm=19886NBR would be the normal material used for engine oil unless in a particularly harsh environment when Viton might be used, but Viton is not a generally preferred choice if NBR is adequate.
I doubt it's a directional design (with spiral features), that's usually only if there are undesirable pressure differences each side or potentially larger radial movements, neither would be the case for camshaft seals in the Capp.
If it's a standard size then most bearing stockists would probably have them, I've used the link before with no issues, also
https://simplybearings.co.uk/shop/ and
https://www.bearingshopuk.co.uk/