Spin-On Oil Filter
Thanks to John Evans for this ...

Today I converted the oil filter on my Cambridge to a spin on type. I bought the kit less filter off  'Mattyzx' on ebay  for £19.99 plus postage thanks to information given to us by Einar.

The ebay shop is Matt Lewis Racing. I bought it and paid for on Saturday night and was delivered today (Tuesday).

The kit contains an unit in 3 parts with full instuctions which replace the original filter and took me about 1 hr to change it and the oil with good quality 20/50 mineral oil.
I bought the oil filter from Partco for £3 and the oil for £14.
It is listed as fitting Mga, B, & TF. But basicaly fits 'B' series engines. 
I had to use the original oil filter seal as the one supplied was too thick. My filter seal was only fitted last year anyway and was in good order.
I have taken it for a run and pleased to say 'no oil leaks'.