B31 rigid-plunger

[GLENN]

I reckon it does match!  Just went and had a look....very limited space, but it does look similar.  Just sent you a message

[V500]

The one in the pic I posted was the  earlier 1946-48 one to match the older light-weight 'box (I have the later M20 style box) so not suitable, and the one on Ebay sold for an incredible £440 c/w over-stamped (therefore useless) front frame.
So sadly the search goes on.