Personally I think it's probably a locally made razor, there are a lot of Gillette copies made in India and the workmanship on the inside of the silo doors doesn't quite look right somehow for a Gillette. Looks like a homage to a slim adjustable. I'm nothing like an expert mind you, I'm just your bog standard shaving enthusiast and thankfully we have more knowlegeable people here.
Beejay is right that sometimes special items are commissioned to promote brands. Old Spice never made their own razors as far as I know, but yeah, could be promotional tie-in I guess.
Having said all that it's still very interesting and £2.5 is a bargain for such a nice nik-nak.