This type of front stand was fitted in the 1948/49/50 era, certainly to Square Fours. I had one on my 1948 4G and there is a photo in "Square Forum" of a brand new 1948 4G, agin fitted with this front stand. I don't know whether they were fitted to other models at the time or whether perhaps they were just used on the Squares to reduce the danger of these heavier bikes falling over.
36 4G, 37 VH, 54 KH(A), 75 Healey 1000/4, 52/53 ex ISDT KHA (project).
Former Machine Registrar & Archivist, General Secretary and Single Spares Organiser (over a 25 year period).
Now Archivist once more - but not Machine Registrar.