"Are there any articles or mention of the rare Clyno 2 stroke model with a displacement of over 300cc instead of the usual 269cc?

I had not heard of the smaller motor until I posted a picture that came from a glass negative I bought on Ebay. An eagle eyed gent spotted the Clyno with the sidecar was belt drive, and not the usual all chain drive twin, and he mentioned that the sidecar looked like a lightweight version that could be attached to a two stroke Clyno. I can't remember the displacement, it was 315cc or 325cc, and was said to have been a very limited production run. Bob Curry from one of the classic bike magazines mentioned he had a 2 stroke Clyno, and that the top of the cylinder had broken off the base spigot, and rendered it useless, so the extra capacity may have exacerbated this flaw and the model was dropped, and not mentioned in polite company thereafter."

Gerard Pentland in Early Motorcycle Literature
Howard Burrows replied, "...there is one of these featured in Titch Allen's Vintage Road Test Journals"