Hi everyone.I have just sold the above on behalf of a friend but it's got me wondering what mark it is,the serial is 18831 and there are no dovetails for the front sight just a slot on the top of the barrel roughly 4mm wide and running paralell with the end of the barrel about 10mm from the end.I have heard about a fwb sport with a wrap around front sight and of course the mk3 with the muzzle weight and sight built in.Is it possible to tell from the serial number which mark it is...Thanks...Lewis...