As far as I can tell ALL the (EDIT: import) 24mm and 16mm pot wafers are made by only a few east Asian factories and the metal parts, only two or three. Sometimes the different factories parts are swapped around a little. I expect they're somewhat standardized to each other for conveniences. But basically all the pots are now pretty much the same as the import Alpha Taiwan pots we've been buying from Mouser for decades. Though most come out of China now I suspect that the Taiwan pots often did too. The exceptions would be in QC. Bourns, for example, has very good tapers and tolerance as well as offering special bushings and torque lubricants for the industry. But the mechanical parts are all pretty much the same. That said...
I've ruined a couple of the old Alpha Taiwan pots attempting to solder to the rivets. As far as I know there is no conductive medium between the rivets and the track. They are only compression fit. So I suspect that flux creep was the problem. But then I've successfully soldered many to the rivets also. I think if you use a hot iron, get in and out fast and be sparing with the solder you'll be ok. But my point above is that there's no guarantees. If you find that you have to keep resoldering your make shift pins to the rivets because heat transfer is melting the joint when you solder the other end then you stand a high likelihood of compromising the connection. If you have room you might try clipping a hemostat on the pin to act as a heat sink. Again, use a hot iron and get in and out fast. Maybe 700° instead of 610°. If you have to hold the hot iron to the joint for too long to get flow there will be more heat transfer and risk of re melting your rivet/pin joint.
EDIT: CTS is making 24mm and 16mm pots. I do not know where they are made, but they are different from all the east Asian import pots.