Wiper arm spring source?

After 48 years the rusty old spring snapped in the Anco 15B arm on my Charger.
I've searched but the closest I've found is listed as a GM part: Brand X parts
It looks very similar and it's stainless, too...
Anybody know where to look?

I'm not a numbers matching kind of guy, when the spring broke in my wiper arms, I would replace the arms with new ones. Usually by the time the spring broke, the hole it hooked into was tearing through as well. Gene

PM sent.......