Is it a car radio? A few years ago when the radio quit in my Buick the shop-South Park Tire Factory sent it to a shop(Kent?)that rebuilds radio’s. They fixed mine and it worked good. Otherwise if it’s for your home you’ll just have to start calling around to shops that sell radios and see if they have any leads. I suspect you’ll have a hard time finding a repair shop. Best bet is you’ll have to find someone that does repairs in their basement as a hobby.
Not sure on your time frame but this event Tues at the Burien Library might be what you need. It is on Tuesday but there are other dates around the county.