I live in Canada, but I lived in England for a year in '68-'69 and when my "A" Marine Band gave out I went to a music store to buy a new one. They had never heard of Marine Bands, but the Echo Vamper was exactly like the Marine band except for the front cover plate which said Echo Vamper instead of Marine Band. I still have that 38 year old harp, though I seldom play it. I prefer plastic combs now.
pavane mentioned that they all have plastic combs now, but I think the Marine Band and Blues Harp still have wood. I remember soaking the wood harps after reading an artical in Sing Out! by Tony Glover. The wood swelled up and I had to shave it off with a dry-wall knife. I think the soaking was not designed to affect the comb. but rather to make the reeds bend more easily.
In those days harps were about 3 or 4 bucks and it was no big deal if you had to buy a new one.