Over the more than 48 years I have been involved with BJ8s,I can’t remember seeing an aluminum (not chrome) front emblem. I have seen a number of odd Original parts onHealeys (mine came through with a piece of nicely formed engine colored angleiron as the front pivot of my HD8 carburetor linkage) so it is always possiblethat your emblem is original. However,although there is an outside chance your emblem is original, I would expect itwas probably acquired from a third party provider and installed some time inits post-manufacture life.
I would like to see pictures as most original chrome emblemsare now shallow of chrome. Remember, backthen, most polishes contained some abrasive as a cleaning agent.
All the best,
Ray (64BJ8P1)