Etched Silver mug

I picked this up today at an antique shop. There is a marking on it but it looks like part of it is gone. Can you identify what it is and if it’s even silver?


The mark looks as if it is almost certainly EPNS (and probably a figure 1 after). EPNS is electroplated nickel silver. The brassy finish of the outside of the mug backs up that diagnosis.

Phil