Plus one regarding Agedhorse. He helped me out when my GB needed repair. The guys at Fender sorted out the repair but only able to do it because they found another amp & took the part that I needed from it ! I asked about parts for the future & the guy shrugged & had no idea if it would be possible.
I decided to sell my GB after that which was & still is a major bummer. Best amp I've ever owned. I hope you get sorted.