Yes the "Greenlander" was WW2 British Army and kind of looks a lot like the Mark11 and Big Indian. The size you mentioned is definitely WWW Longines. The Big Indian, I don't think there is any information about if it was used for flight or ground duty (at least that I know of). The numbers for the casses go over 200 so we know for sure there are more Big Indians issued than the Mark11 which are between 100-49 and 199-49. Most of the ones I know of are around 170s. My friend's is in the 110s making it one of the lowest numbers I have seen. WWW are usually in the thousands issued so quite common.