Well here is my 1948 BSA M21.
[Linked Image]

And my 1961 BSA A10 Gold Flash.
[Linked Image]

And if you want to read the M21s Diary... http://www.ljswain.btinternet.co.uk/pictures/m21/m21.htm

1940 BSA M20 500cc Girder/Rigid- In Bits!
1947 BSA M21 600cc Girder/Rigid-Green
1949 BSA A7 500cc Girder/Plunger Star Twin-Black
1953 BSA B33 500cc Teles/Plunger-Maroon
1961 BSA A10 650cc Golden Flash-Blue
1961 BSA A10 650cc Golden Flash-Red