Originally Posted by
gr23932
I think it reads "Norta"??? If so, I think it was an old Belgian bike brand. .
Yes, should be the signature of the belgian bike 'maker' (really more of a wholesaler) from Herentals/Olen.
Probably produced by SR ~ Sakae Ringyo (model "Apex"?), but on behalf of Norta - not too unusual at that time.