I don't think it is likely they were the TA cranks which used a rather odd kind of cotter and a special axle. Cottered aluminium cranks were not that uncommon in the 1940s and 50s. Weinmann made them as well as Duprat (my Barras has Duprat aluminium cranks) and Holdsworthy (Allez), Granby and Hobbs (Lytalloy) all offered cottered aluminium cranks which look as if they came from the same forging. They turn up fairly regularly in the UK although they cannot be said to be common.
Seasons Greetings to all CR members
Hilary Stone, Bristol, England
> DavidS4410@aol.com writes:
> << I the mid 50s, I had a Royal Enfield bike with cottered alloy cranks. I
> don't recall the brand. Has anyone ever seen or heard of these. It was a
> single 5 pin chainring setup. >>
And Stevan Thomas added:
> I believe T.A. made a set like that.