I can help here, I have a few Hobbs (one bought new by family member in 1952), the model depicted is a Clubweight and is of welded or fillet brazed construction (i.e without lugs - lugless). It will be constructed from either Accles and Pollock Kromo tubing or Reynolds 531 - both are excellent tubesets.
It is a postwar frame, with the number I can date it, the frame is missing its seat tube collar - this enables the set post to be tightened in the frame. Hobbs did not build frames after 1953.
What is a very rare and superb thing is the brass and glass enamelled headbadge, few frames seem to have this (mine have, see image).
Hope this helps.
P.S Hobbs badge is not my"best"Hobbs - simply a spare one!
Co-founder of a V-CC section, member South Eastern Road Club and owner of - 2005 Bianchi Reparto Corse (modern), 1985 Raleigh SBDU Pro Super, 1984 Raleigh LU Corsa, 1980 Allin Stan Butler Special, 1978 Ron Cooper, 2 x very ealry Roberts (late 60s/early 70s), 1975 Bill Philbrook tourer, 1966 Raleigh Superbe Roadster 1964 Allin Stan Butler Special Belgique, 1951 Hobbs of Barbican S/C, 1950 Hobbs of Barbican S/C, 1947 Hetchins Super Special, 1908 Centaur Featherweight.