could it be the 303b
? I couldn't find it on this page
(awesome site for old camera manuals btw)
only disadvantage i can think of is how difficult it is to focus in the viewfinder of a crop body. live view works very well, but it just doesn't feel the same as using that focus screen in ur film camera or on a FF body. this is just my experience though, some ppl can mf tack on in the viewfinder on a crop.
i think your options are:
1) an adapter with glass (which you can remove for macro photography)
2) someone modify them permanently ($$$)
i wish my dad played with photography cameras instead of video cameras haha