Very interesting question Richard. Hope you get a reply.
Ive noticed that there's very little detailed information online regarding previous generations of reels. Much more information available for such things as previous generations of bicycle components - old catalogues etc..
Thanks for that bj, it is a very informative and useful source of info for the collector, if not specific in this particular case. It does seem to indicate that Some Perfects were fitted with small feet in the fifties, earlier than I thought, but from experience I don't think it was a universal change to all reels at that time.