I have one of these sets, too. Does yours have the mirror tucked into the slot on the "lid"?
The razor is silver plate. I'm not sure about the tins & blade boxes.
-- Chet
The tins and blade cases are almost definitely nickel, but the razor looks silver-plated to me. What I found particularly unusual about that set was that its serial number, which matched from razor to box according to the seller, would put it well into 1921.
It's a shame that the mirror went walkabout at some point during its life. Otherwise it'd almost look like unsold stock. It certainly never saw any amount of real use, from the look of it.
I do not know if the mirror is tucked away in the lid or not.
The seller said the mirror was missing in the description, but you never know.... Maybe they didn't know what they were looking for. Even so, as long as there aren't any nasty surprises when you get it, I'd say you did fine.