MMMmmm.
Never dealt with feked, so
Dealt with Armours many moons ago; no aeons ago. Purchased their pattern silencer for my 1953 AJS18S in 1975 and found it to be of reasonable quality and, of greatest priority with these models, 'free flowing', they hate being over baffled!
Also bought a Goldie silencer from Armours for the Duke 450. Heavy metal, good chrome, fittings OK, but over baffled and choked the Duke most horribly, so it is now 'Wall art' in the shed!
My regards, Bill