Such charming little buttons! They read as brass, but under magnification I believe they are some other metal and painted a brassy gold tone. I have not found others like them and think they have a fair amount of age. Fun sewn onto a favorite coat or cardigan, but I might string at least one of them on a chain to wear as a necklace...surely causing all doors to open before you!
Checking dimensions. Sold as a set of 8. Very good vintage condition, with some wear to the paint as pictured, only noticeable upon close inspections. Images are shot at 2x magnification.