Don,
I have bought repro XS1B/XS2 turn signals from Jerry Heiden, I am sure they are the exact same ones that MikesXS sell, as Heiden and MikesXS are sort of partners.
My bike is a 77, so came with the newer type turn signals, but I wanted shorter stalks and that "older" look.
The quality is so-so in my opinion, and that is without the bike rolling a meter so far with these lights. I would not expect the chrome to last particularly long, and they somehow look "cheap" when examined closely. But I have never actually looked at the OEM lights from the earlier models, they may not be perfect either.
But I am still reasonably satisfied with these, as the set of 4 are more than a pound lighter then my stock -77 lights, have shorter stalks for a sleeker look, and as I said before just look older/ more classic IMHO.
I guess it is all about what you're after. For a 100% restoration of an early bike, I would say they may not be what you are after. For function and general looks on a daily rider or modified bike like mine, they do the job. At least they look like they belong on the bike, unlike all these "mini turn signals" people put on their bikes these days.