Thanks, lots of excellent info, but the best data I can find on the Foster Series 2 is this:
Converting the imperial seems to come out about right on the outer diameter and length, so the reduced diameter element I can only guess at but they look "right".
Does the Foster Series 2 use a valve? That element seems like the show stopper, and I don't think the Foster 2 is a dry-dry connection and not sure which, if any half, is dry?
If anyone has already tried or can add anything feel free to shout ... otherwise we'll just have to have a go and see who gets covered in fuel