B and M Series plunger bikes share the same basic pressing, just with the addition of easily removed extra brackets. I did wonder if that guard started life on a Star Twin. Back in the day you could get new universal guards and cut and shut to fit. Probably still can now, but true time worn originality will cost.
With the interest in old bikes, ebay, clearing out Grandad's Shed etc there is more choice than ever before. Used guards are a gamble, shot blasting anything composed of atoms loosely associated is bound to lead to mental anguish.
Swarfy.
