Injector Seals - Correct part numbers

Does anyone know the correct GSF part numbers for the two injector seals as shown in the illustration at the top of page three in the link below?

http://www.vwgolfmk1.co.uk/Main/Testinjectors.pdf

I've just got some from GSF - one seems right for the top (GSF part #18720) but the other is too large a diameter for the bottom.

Does anyone recall which is which?

Cheers