Cal-Leather Belt Loop Snaps

[Kane]

I hope that I’m not rehashing old ground here, but I am curious how the belt loop snaps on vintage Cal-Leather jackets factor into dating and assessing the jacket. I know, from looking at postings here, of two type: exposed brass colored snaps, and black painted silver colored snaps (usually with most of the paint worn off). Are there other variations? What is the significance?

Thank you, and Happy New Year!