Steve
Even though the 65sa is small, the 47sa is even smaller, and although olympus lenses are also small, there is about 2mm all round between the back element cluster and the helical inner. I did have doubts as to whether this would be a problem. I used 50mm 1.8 standard lenses, and if yours is anything like mine it needs the slot moving internally so it can be light tight. Incidentally to seal up the old slot in the helical I used some sticky back thick felt like stuff (b+q) that is supposed to prevent door handles banging against a wall or something. It is thicker than the thread is deep, so the felt lies jammed in the old slot, and takes on the profile of the thread, and is totally trustworthy even when the lens is fully extended. This was the only way I could figure out how to fill in the slot and make the helical and the old slot light tight.
I found mounting the new lens onto the helical required making new 'boards' - no probs if there are old ones kicking around.
Schneider have flange to film distances on their web site.