beauty of a piece!.. I have seen the exact pin arrangement used in the late 20s, 30s, 40s, etc... But they are still used sometimes even today.

- in the 70s it would be real enamel too and looks like it.. I'm thinking 70s as IF it was earlier there would be a hammer and sickle on it [?]

. A very hard piece to date exact . maybe there is some kind of catalog, advertisement etc. that will turn up..