Turns out the frame was built by the builder (John Mortimer), for himself in 1972. Mr. Mortimer was an optician by trade, a long standing member of the Wimborne, Poole Wheelers Cycling Club, a keen racer in the 1950s & an amateur frame builder.
He built frames for friends from the early 1960s-1985/6. Building just 60 some odd frames in total, including nine tandems & four trikes. His tubing was purchased in the early 60s from a builder (not known), getting out of the trade. Tubing was Durifort, no lugs were purchased. Thus he never used lugs. Serial numbers were on the bottom bracket in the form of the owners’s address with year built on steering column.
Mr. Mortimer got bit by the motorcycle bug when in his 50s & seems to have left the bicycle behind in it’s wake. He passed away in 2022 in his late 80s . Information was attained from his son & two long time friends
My frame was sold off with his garage contents in 2006. I’m waiting on a photo of the transfers to reproduce for restoration.
Thanks again everyone for the help especially narrowing down the location