According to an expert, the frame is from a Monark 1929 350sv.
As it happens I have a sutable engine (should have been a Blackburn), a JAP 350sv from 1929, featured in another post in this blog. I also have got a 1929-ish Albion 3 speed gearbox (should have been a Burman) that also fits the frame.
Featured in the picture is a Husqvarna 250 1929 oil tank. Got it cheap, did not know why, not before I started looking for an oil cap. Had to buy a new replica oil cap and thar was not that cheap.
Rear wheel has now got a NOS Trelleborg Trial tire.
The seat is a rear seat from an unknown bike. But in wery good condition and from the same manufacturer that made seats for Monark, Husqvarna, Rex an other Swedish motorcycles at the time.
Slow but steady progress, not.
