Since I've just joined the board, this reply is a bit late. However, I can certainly solve some of the mystery.
I-OMMET, pronounced 'yummet', is the mark of the metal-working centre of Mstera Jewellers. The number in front is, I believe, some sort of date code, but I haven't yet cracked it. Yours is probably a '5'.
There should be a second marking that looks somewhat like 'u?p??K', where my ?s are replaced by numerals. The 'u' is really a Cyrillic 'ch' and is short for 'price', 'p' is the Cyrillic letter 'r', and well, 'K' is 'k'. This represents the original price in rubles and kopeks (100 to the ruble). It says something about the old economy of the USSR that a price would be permanently stamped on an item.
The metal of the holder is melchior, an alloy developed by the Russians to mimic silver, which it does exceedingly well, often even fooling the experts. I spend a lot of time on ebay convincing sellers that, no, their item is not sterling, and not even silverplate. I don't think this makes me very popular. :-)
The glass liners certainly tend to vary in quality: some of them are rather wavy and crudely made. None of them are what I would call fine glass. Despite all this, I have a large collection of this type of salts.
Lea