I am quite sure I know the ans. but as I am off to my LHS tomorrow in the city for more parts....F7Bs....full sets of hoses both ends? Must be. How else would they fit into ABBA units, eh?
Of course, both ends and both sides.
Of course.
But I do notice that I don't need as many diaphram sets as I thought. The archive pictures show many if not most B units without. I suppose this is true of A units as well? I did install diaphrams on several other AB sets anyway.