Some interesting items there Garvin - thank you. I initially wondered if the .25 Standard could be the mythical No3 Standard that John Knibbs referred to briefly in The Golden Century and of which no examples are currently known. The T Series Standard would be too late for this however and having given it some thought, I wonder if the N03 Standard was intended as a shorter cylindered .22 rifle (43 1/2" overall)? It would make sense that BSA would have come to the conclusion that a shorter and consequently lower powered .22 would have no advantage other than shorter length over the well established N02 Standard at around 1930 but a 43 1/2" .177 would be popular. After all, that was the length that started it all.