I know what you mean.
IMO, by most standards, Fraser made only "Best Quality". In design and execution they are tops in my book.
Some Frasers got the gold treatment and others did not. Same goes for Fraser single shots.
Not sure if that was something the purchaser could specify or just that some got it and others didn't.
I would like to see some period Fraser literature to see if the gold plating is mentioned anywhere.
Anybody here know for sure?