BSA cast units for comparison, and a trigger guard.As you say further ops are done in some cases, ie. the spotface and tapping of the guard in the second picture, but honestly although old air rifles are often better made in respect of using castings and forgings, and aesthetic touches, most is very basic in terms of engineering and often just removing sharp edges and the like.
Older air rifles are just like anything else made say in the same period, be it tools or cars / motorbikes etc. before the bean counters took over.
ATB, Ed