Took the Velocette on a poker run with a bunch of (98) Harleys and met a guy who said he had some pre-unit BSA parts. Bought most of an engine and a tranny. Engine numbers are weird. Stamped HHC, but flat top pistons (.060 over), thick flange cylinder, iron head with bottom fin broken all around. Figured maybe I can have a spare engine, or at least parts. Wondering about the brass spigot(?) on the primary cover. Auxiliary breather?