High Standard Sport King .22LR

[TJM]

Recently inherited this gun from my father - it had been well used by him back in the day, but recently has been sitting for a decade or more in his gun cabinet without seeing the sun.
Long story short, shortly after receiving, noticed some issues and took it to my local gunsmith who diagnosed the problem as a faulty firing pin. He was able to work the pin back into useable condition, so the gun will fire, but he promises that in very short order the firing pin, due to metal fatigue, damage, etc, will stop functioning.
Given this model has been discontinued for some years, any leads on how I might get a replacement firing pin, or even have one made? My gunsmith had a lead somewhere in the midwest (I'm in NJ), who apparently can machine new parts, but it's been about 4 months now and still no new firing pin.
Just curious if folks had any suggestions. While I'd like to have the gun in useable condition, I also don't want to end up paying so much I could just buy a new gun.
Thanks for any thoughts, input, etc.

Tom