$hit I wish I had known that. Then why the staked set screw? Would these heat up enough in use to melt solder?
This may not be a 100% rule, but the only ones I have seen that were soldered were Izzy kits. Maybe it was done on some U.S. inventory, but I have not seen it. It seems to be mainly another one of those Izzy things.
As to soulreaper's issue, these are always a pain. There is an available surplus socket that is designed for the booster removal, but the issue remains how to get a solid grip on the bearing without mangling it too much. Many of us have found the marks of vise teeth on our bearings, and it's no wonder. One member here told me of making a vise jaw adapter, out of wood as I recall. That enabled him to hold that bearing solidly without damage, while turning the booster cap off. An air powered impact driver has been suggested, but again the booster needs to be secured from rotating.
I would go with Mouse's suggestion and soak it to minimize the carbon issue, and then use a vise with toothy jaws. Unless you are going to do a lot of these, it is probably not worth making special tooling. Besides, a few teeth marks will look authentic.