Starfire III '66 beauty, Bigsby help needed!

[Guildedlily]

I've seen that occasionally. far from an expert, but in short...while most guitars probably need the TR tightened over time, some need the opposite. just one of those finicky things with the wood. with the guitar tuned up, set the neck relief to where u like it with the truss rod. this could require loosening or tightening, and over time and change of season, string gauge, tension etc, u may find it needs adjustment in either direction. don't force anything. if something doesn't seem right, take it to professional luthier.

Thanks @mavuser

I took advice on this from a well-known and excellent guitar builder. He said that yes this is a legitimate thing sometimes - to slacken the trussrod all the way off. Guitar arrived with 8s on so when I put some 11s or 12s on I'm imagining I'm going to need to tighten that trussrod a little.

I had never seen this personally, but it's good to know that it's normal.