Mark,

I have manually pumped them in an oil bath to clear all the air, but they are still spongy even when all that comes out is old oil.

I appreciate I cannot replicate 3000 pumps per minute but dont know whether to risk it - I have had lifters from Bren before and they were all plain and worked fine, so I am a bit worried that some VW ones may have got mixed in which apparently are slightly different, but I guess even so these would pump up just the same.