WRT the dovetail on a Cdn no2 pistol: If the pistol has a T in the serial number, and it has the humpback sight, then the dovetail is the result of a frame that was made for the chinese contract being used on a gun produced for commonwealth. It was realized that the guns were no loger able to make it to China so that production was stopped. If the pistol has a CH in the serial, and it has the humpback sight, then it would have been a gun made for the initial Chinese contract, delivery was suspended, and the guns ended up in Canadian inventory. The Canadian army tried to use up that inventory by using them for foreign sales during the war, and also by filling the Canadian Navy's reqirements. Post war, CDN Arsenals were removing the tangent sights, dove-tailing the slide and installing the humpback sight, thus converting the no1mk1 pistols to no2mk1 configuration.
On unification of Canada's armed services, the DND was now faced with supporting the non-standard Chinese guns. They were removed form service and replaced with standard no2 pistols. Whether those pistols removed were upgraded or disposed of is a question. There were still plenty of brand new no2 pistols in stock right to the end of the service life of the no2.