Gearbox seal sizes / dimensions

I need to fit a new input shaft seal while I'm doing the clutch. Can anyone tell me the dimensions of this seal? The one I've just pulled out is now too knackered for me to measure the inner diameter! It measures as 40mm o/d and 8mm thick though.

While we're on, if anyone can give the sizes of the diff seals too, that'd be great. It's a 5speed 83 GTi by the way with transmission code 7G.

Thing is, I'd rather buy them separately from my known-quality seal supplier in  Peterborough, than buy a kit off ebay with seals that are probably made from old shoes in a cracker factory in China.

Wierd thing is VW told me they no longer supply but gave me dimensions of 35x23x6.5 (from the parts catalogue thing they use.) Went to a seal supplier in the week and they say that's a non-existent seal size! So they gave me a 35x23x6 instead. Obviously this 35mm seal isn't going to work well in a 40mm recess.  

i got the seal kit off ebay,the seals are the same make as the vw ones i took off the gearbox!
good kit for ?15
Bert