Diogenes on The Barbican (title uncertain)

Diogenes on The Barbican (title uncertain)
Media: 
Oil on board
Size: 
33 x 43cm
Signed: 
Yes
Sitter(s): 
Edwin James MacKenzie, aka Diogenes, born 1912, and unidentified sitter
Additional Information: 

This work has been thought to belong in Project 6, but may be Project 1: Vagrancy: perhaps No. 19. Diogenes and Harmonica Jim, £65.
If not that, the second man looks like David Helingoe, but no such work can be identified in any Exhibition list.