Well yes & no, it was in Military guise but a civilian model & then some one sporterized her & I don't think that was Andrews the English rifle builder .
It had the full Military stock, note the cut outs for the top hand guard & the cut out for the Volley sight on the side, also the action was milled for the Volley sight, the later BSA spoters had these filled in like yours & some very few others that were made by rifle builders .
I have a couple of these & one that was a Carbine version that has no machining for the volley sight .
One thing that is unusual is your looks to have a Carbine trigger Guard & for sure has a Carbine or sporter magazine, hence me asking about the rear sight placement .
I think you got a good deal any which way & should be pleased with the rifle, I bought one like it (not Lee Speed marked) in the UK deactivated just for the magazine & got them to resell the rifle as I need a few mags for the rifles I have, I would have bought yours & done the same if I had seen it !