See what you mean: the Yamaha Revstar doesn’t have Yamaha on the headstock, but does have the tuning forks.
But other Yamahas don’t have the tuning forks but do say Yamaha. Eg. https://uk.yamaha.com/en/products/musical_instruments/guitars_basses/el_guitars/sg/index.html
I think there was a period, pre Revstar, when motorbikes had the tuning forks but none of the Yamaha guitars did.
Yes, I think the US pint is 16 Oz (2 cups), whereas the UK pint is 20 Oz (4 gills).