I don’t think the original resonators were screwed in, generally only resonators that are sold separately (and meant to be kept in case of an overhaul) have a screwed construction.
You can buy such resonators from several makers, I have the ones from tenor madness. Metal, domed or flat resonators, seamless or riveted, are available with many tipes of pads and unless you have a special reason to want to buy a set of separate resonators there is no real advantage in acquiring replaceable resonators.
A tech will not particularily enjoy to have to fit screwed in resonators because it adds a time consuming activity to the already long process.