Rose Gold Powders
I used to use these all the time for buttons, badges and sword hilts etc. And still would if you could get them. My last lot were in the flat brown bottles and a little went a very long way. I used to use the Rose paints as well. But that's all gone now...
I still prefer metal powder for painting metals. They are usually called "Bronze Powders" and you can get them from various art suppliers. I like to use Roberson Bronze Powders which I buy from Cornelissen in London. You'll need a medium for the powder to make paint. I don't know what the Rose medium was but I always guessed that it was Japan Gold Size, which has been used in gold leaf work for years. Japan Gold Size is slow drying, which is supposed to be a good thing for metallic paint as it allows the metal particles to rise to the surface as the paint dries.
Well indeed, don't ask me. All I know is that it makes a bright metallic finish which dries overnight and stays bright.
Nowadays, I use Winsor and Newton Japan Gold Size. Dip your brush into the size then dip it into the powder. Slosh the brush around on your palette to mix into a metallic paint. Lovely stuff.