Thanks all! Some new things seen on the links, which is great! The catalogues so far as I have read don't mention 531 tubing, and the wee beastie has 531 respray decals. Also, the rear triangle is part chromed, and the rear brake cable is external through 3 braze-ons not internal. It has Simplex stamped on the drop outs and only one set of bottle bosses. So far nothing matches. The search continues...

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