tophat question

where can i get a new tophat?

mine works loose and i suspect there has been one of the setscrews stripped or lost as it does not accept the correct allen key.

it’s way i got it from the dealer i purchased it from. i noticed it was moving while i operated the cocking knob during the final step in loading.

tightening doesn’t seem to help; i don’t want to overtighten and it works loose.