Can any one identify this clutch part

[7iain7]

I am in the process of rebuilding the Engine on my A10 1952 plunger 

This part has broken and i want to order but cannot find the part number.Its from the clutch assembly
Many thanks Iain

[limeyrob]

Its not broken, its comes as a ring that you snap in half to fit.  (Assuming you mean the two half rings)
67-3251
Comes like this with notches:
https://shop.sparesservice.be/gearbox-mainshaft-split-washer.html?___store=fr&___from_store=du

[7iain7]

Thank you so much

[limeyrob]

I know because my first bike was a C11G and it has the same part.  I went off to the local BSA dealer, bought one, about £1, very pleased, got home and realized the only way you can fit it is to snap it in half .