The stamping - large letters and smaller numerals is exactly the same as that on my 1936 Square so I think the stamping is original. It was definitely an export bike so there is some history somewhere as to how it came back home again. As in most of these cases, we shall probably never know the answer.
36 4G, 37 VH, 53 ex ISDT KHA (project), 54 KH(A), 54 4G Mk IV (project), Healey 1000/4 (project)
Former Machine Registrar & Archivist, General Secretary and Single Spares Organiser.