According to my files, the Burman part number should be -3BA for the inner cover or "kickstart case", as Burman described it. I believe that it is the same as the part fitted to CP-type gearboxes. The only variation I recall, offhand, is that the hole in the lug through which the clutch cable passes is threaded on some non-Vincent-HRD 'boxes for cable adjustment whereas the hole is plain-bored on postwar BAPs fitted to Comets etc to accept a split ferrule, the cable having an in-line adjuster.
To summarise, the Burman part number should be cast in relief somewhere on the inner case.
PK