I have A.G. Parker s/n 0019, which has no markings at all apart from the A.G. Parker crest on the Knox-form. It started off as a Lee-Metford Mark II and was sportered about 1920.
Under British law, it is possible to remove all the markings from a firearm on rebuild, just so long as it subsequently has new markings added; it then is sold as a "new" firearm.
I also have encountered a Mark III* SMLE marked GRI 1943 and with ENGLAND stamped on it rather prominently. It looks as if the entire Akrika Korps ran over it with their Mark IIIg panzers, but it's all there. India supplied quite a few SMLEs during War Two. Many of these made their way to England and, after the War, were surplused. It was at that point that they were stamped "ENGLAND", even though actually not built there. Following this, they were sold on the international market (that means to us) or handed out as military aid to armies which were re-establishing themselves following the Occupation. Norway, for example, was almost totally bereft of Krags, Greece of Mannlicher-Schoenauers and so forth, the Nasties having moved them all over the map to stop the locals from shooting little round holes in those nice square helmets. But the "ENGLAND" stamp at least gave one an idea where the things were coming from.