Hi Edward,
you are a lucky guy - it is definitely a silver dial with hard black enamel. Seems to be from the Stern company in
Switzerland according to the back markings.
It seems as if it has lost most of the lacquer - maybe it has been removed because it had aged towards yellow ...
With the clear lacquer the printing "Omega" has gone as well. This is not a great issue.. as the rest of the dial is original.
If you want to improve the dial you could have it re-coated with clear lacquer and have the word Omega added...
BUT!!! Let it be done by the best of the dial restorers and tell him strictly NOT to replate or to change anything else!!!
Otherwise the value will be lost dramatically! If you want me to assist you please send a PM.
Otherwise keep it as is - but there is the risk that the silver turns dark over the time - as there is no protection through the clear coating.
It is a hard decision, think it over carefully.
Kind regards
Erich