I'm planning on having my corroded wheels powder coated and installing new tires. I was considering replacing the OEM metal valve stems with something different.

The car doesn't have TPMS. I was able to break the outer bead on one of the front wheels today using my cheapy HF bead breaker. I was hoping to remove the metal stem and confirm the hole diameter and wheel thickness to see what options I have for replacement valve stems. The metal valve stem appears to be 10mm diameter with a 1/2" long barrel nut on the outside. There is a gasket on the inside, the barrel nut presses directly on the outside of the wheel. I screwed a valve stem insertion tool onto the valve and tried lightly tapping on it to drive the valve stem into the wheel, but it wasn't moving at all. It seems like the valve stem is threaded into the wheel. There's a slot across the button on the inside, but I couldn't get a screwdriver on it with the tire still on the wheel. So at this point I don't know if it's threaded into the wheel or just stuck from corrosion.

Most standard valve stems are meant to fit in a .453" or .625" diameter hole. This 10mm hole is only .394" diameter.

Have you ever seen this arrangement with the valve stem threaded into the wheel? The valve stem and barrel nut appear to be stainless steel and aren't corroded, so I'm thinking they can just be reused.