I tried telling the seller but he(?) insists it says 501. Despite all - I think - 501 decals have horizontal numbers I. E. not sloping. Shan't bother anymore. I think it's been over restored anyway.
Well done! So knock the pug and Raleigh out cheap and you've got a bargain McLean. Excellent. Look forward to seeing more pics. And then a sensitive refurb?
I've done a little more research. This bike, and others like it produced in the early 60s, represent the pinnacle of Langsett production. Sadly, like many small producers of the time, they found it increasingly hard to sell their output - their last bikes of a long and fantastic line were made...