Hugh, I was just looking at the vacuum pump on your site and noticed there are two seals listed. One is 53mm and the other is 56mm. Which one is correct?? One seal says it's for pump with P/N ending in E, and the other one is for pumps with P/N ending in F and G, but the latest revision is H...I'm guessing the F/G seal (56mm) is the correct one for the H pump, but would like to verify.

http://www.europaparts.com/vacuum-pump-06d145100h.html