From what I’ve been able to piece together, pretty much any shop that could sell motorcycles/scooters did so. There was almost no brand loyalty unless you were buying from sears or MW (even then, there were lots of brands with the house brand attached to them)
I have a Black plate style plate frame that came off a S1, it reads Riverside and scooterramma.
I Purchased a 1963 LI150 barn find more than 10 years ago that had a “Riverside FORDYCE” Dealer license plate frame on it. It had the Origional Black California License Plate on it as well.
The problem is these nylock nuts are not meant to be reused. Here we are some 50-60 years later still using this stuff!
If you are going to use original hardware always use a new wave or lock washer and add a drop of anti seize grease on the threads of the nut. This way you can get the nut all the way tight on the stud and you won't risk them going loose on you.