Q: 65 Thunderbird all wheels locked.

The method to release a stuck parking brake on your model depends on where the fault is. If the cable is seized to the sheath, then the cable will have to be released (cut) within the drum brake assembly. If the lever in the brake assembly is seized, the brakes will have to be disassembled, cleaned up, and lubricated with an anti-seize compound. If the front brakes are also not releasing, then it has to be determined if the master cylinder (or a stuck proportioning valve) is not releasing. It sounds like you might have a larger issue and I suggest you just request a comprehensive brake system inspection. If you request that service, the responding certified mechanic will get this diagnosed and resolved, right at your location. If you have further questions or concerns, do not hesitate to re-contact YourMechanic because we want you to make the most of your repair dollars and help you to get the best possible results.