I picked up a razor the other day at an antique store. It has black scales and is marked "Made in Germany" on one side of the tang, and "Hare & French" "Bismarck N D" on the other side. The blade has "Guaranteed" on it. The razor is in good shape, but has an oily tar like stuff that I have not cleaned off yet, so some of the above could be a bit off. I can't find anything about the razor. Anyone know anything about it?

Thanks