Recently examined a British P1888 bayonet scabbard which is different in that the mouth piece has the three rivets standing proud of the mp and a small tear drop shape frog hook. These are features of the later P1907 MkII scbd. This will not accept a P1907 or IP blade but fits a P1888 or P1903 blade perfectly.
There were P1888 scabbards made during WW2 and I am wondering if this is one of them.