Could not match these girders to sloper. There was a cross bar on the BSA non-existent on these that kept me puzzled.
Found letter S1 on the casting that holds the lower portion of spring. Also previous owner had used gas cap on right side flex tension adjustment. Knob there is from BSA WM20 incorrectly used.
When advertised for sale it was listed as M20 girders.
There are two rectangular curved loose pieces on the stem that goes into frame that I do not understand purpose.
Turns out, I have a 1930 AJS with front girders missing since 2007. Used GL3 instead temporarily.
I think using these girders would be more fitting.