BSA, Triumph, Norton?
Have you checked the online Brit bike shops that are here in the U.S.A.?
Sorry for taking so long to respond: It's a 1969 Triumph Trident (T150), the debut year for that model. I've owned it since 1972.
I found a Triumph dealer/service shop in Houston that has a plethora of old Triumph parts, so I'll start there, when I'm ready to divert hip-pocket money toward its restoration. I'm not willing to ride it without turn signals, so that'll be the last thing I revert to original configuration.