I’d try any LCE - There should be one in cardiff, if not I can show you the one up here. Also have a hunt round specialist forums etc - talkphotography has an old photography section that is excellent!
In Cardiff you could try the camera shops in Royal arcade, and Morgan arcade, I think they still do film cameras. Other than that, maybe try a forum like choose-film.com? Or antique shops. I had to find one a few years ago lol