Hi all!

I would like to ask some questions regarding any info about the Bulgarian Naval Engineer - Radio Operator badge. Research looks quite tough -in English language at least...

So far, I know that two (or three?) grades existed, a metal and enamel version for officers and a stamped metal version, which I have seen in bronze and silver.

Are the latter two different versions, for sailors and NCOs, respectively?

What were the award criteria?

Looking at examples offered for sale online, they are referred to as "rare" -and are accordingly priced- but is this the truth?

Regards,
Giorgos