Has anyone replaced the air cylinder on a prewar underlever? and I mean unscrewing the barrel tap loading end from the air cylinder tube.

the reason I ask is, the past year I have been sorting out my Lincoln Jeffries / BSA under levers, a few at a time. I am down to the last 3, one of which is a model d but has a damaged air cylinder, no etching and had crude scope rails cut into it. I also have a scrap model d gun that has a good air cylinder with visible etching but a carbonised barrel. My thoughts are to swap the cylinders and end up with one nice gun.

Anyone tried it?