you know, though, the old mk 1s work okay, about as well as the rest of the machine. they're cool because they're primitive-looking, but they're also annoying because there are so few tuning options. i wouldn't take Concentrics
off a machine where they were working correctly, but neither would i spend a lot of time trying to correct their various issues if they weren't
the VM mikuni carb goes back to the middle 1970s, and so can easily be more vintage than many of the newer AMAL Concentrics
fitted to british machines newer than that.. i've had them on my old morgo T120 for almost 40 years, and i love them.
even the keihin FCRs qualify as vintage now. this design is 30 years old: