Thanks Patrick. I hesitated to draw too much from the serial as so many of these target shooting reworked No4's were renumbered, but I think you're right. I just checked a Maltby 4T in the gunroom & it bears the same crown/N/59 examiner's stamp on the receiver ring. It made me think of Maltby, but the machining of the receiver side wall looks more typical of a Faz/BSA. Probably it's a later war produced rifle than most Maltby's I've come across......