Unmarked Gold Plated Tea Service

I acquired an unmarked tea service which appears to gold plated.Not sure if it’s goldplate over silver or not, but the pieces seem to be rather heavy.
Not even sure if it’s goldplate.Inside of the pieces resemble silver.
Any thoughts from anyone on who may have manufactured this and which metals it is comprised of most welcome.[img]


The general rule is that if metal is not marked as silver (or gold) then it probably isn’t. Why go to the expense of making something in a precious metal and then not marking it as such?