I've had this frame for a while and have never been too fussed with its origins. But last night I was giving it an overhaul and noticed some significant markings that someone may recognise.

Serial Number 1248. There is a II Marked above serial and a faint 'N' or 'Z' before the number

Again a 'N' or 'Z' under the chainstay(this also appears on fork steerer)

Seat cluster, wrap around stays

Drop outs, no markings.
If anyone recognises these markings, particularly the Z or N, I'd be interested to what they are
Thanks
