Cruet set - is it silver plate or not? Help please

Can anyone help with my items?
As far as I know, they are a salt, pepper and mustard set and a sugar bowl & creamer.
I know they are quite old because I can remember them when I was small ( & i’m nearly 50 :blush: )
The spoon has the EPNS on but I can’t see any other marks on them.
They are very tarnished, and reading your site, I realised having them wrapped in newspaper for years didn’t help.
I’ve tried cleaning them a little with Goddards silver pad foaming silver polish and it takes the black away from the corners but doesn’t seem to get through the main goldy coloured tarnish easily.
The inside of the lid seems to have stayed its natural shiney silver colour.
I haven’t seen any others about that have quite as ornate detail on.
Can anyone with what they are made of and what’s best to get them cleaned up?

As the salt, mustard & pepperette are not marked in any way we can only assume that they are plated. I suspect that what you describe as “goldy coloured tarnish” is actually the base metal showing through where the plating has been polished off, although without close inspection I cannot be certain. If that is the case then no amount of polishing will help. If not then silver polish works as well on silver plate as it does on solid silver.