Merkur sold their (own and rebranded) silverhandled razors with a thin layer of varnish so it wouldn't oxidize. With use, that would rub of so you'd get dark/black spots from worn varnish, with heavy use worn silver, or oxidation. The oxidation you can counter with the alufoil/bakingsoda trick, but I'm not sure what that would do with the rest of the varnish, which on your razor still seems to be in real good condition.It's silver but I with a coating. Haven't tried anything to clean or polish it because of the coating (Advice?), I Did shave with it once, but as it is a merkur (which I have) I didn't find it different.
Looking at the offerings of Pomco and Hoffritz, Hoffritz always stuck to the Merkur-variations of razors, where Pomco experimented with other types as well, see Pomcomatic or Lady Pomco. This model I've never seen as a Merkur, which is why I think it's a late (their experimenting took place 60s-70s) model Pomco and not a Hoffritz. Not an absolute certainty though.Using that reasoning, I am believing that the same razor was also presented in a Hoffritz case sometime in the past also: