Threading on pedals is unique to bikes, so it will be an LBS type thing. Standard
repair item in the past, getting to be less common now. Unless you are really attached
to the crank, it would be better to hunt around for a replacement. For low end gruppos of yesteryear replacements can be in the $20-40 range (less for L than R).
Some older shops have a number of takeoffs laying about for low prices. The actual process of repair is straight forward, drill out threads, tap for repair thread and screw in repair thread with heavy duty loctite. The inside of repair thread is already tapped for pedal thread. One brand is helicoil. Since pedal threads are essentially not used anywhere else the equipment is of no use outside a bike shop. Steve