Just purchased this project bike in Auburn, CA. I was told that the bike was purchased from the widow of the owner who raced the bike out of Placerville, CA. No numbers on the motor although it's a 500cc Unit Construction Triumph. I've been e-mailing back and forth with a guy in Sonora, CA who rebuilds these and he said that triumph motors built for race bikes sometimes did not have numbers on them. Also, the cylinder barrel fins have been drilled out (race application?). In comparison with other motors, it appears to match up with late 50's/early 60's units.
Frame number is AM 405 1556. Don't know the manufacturer (hoping somebody out there will know). Fiberglass gas tank is pretty cool with the dual aluminum flip top caps. Any info on the tank and frame would be nice.
If you have any info that could help Alan, please get in touch.