Welcome! The 5427 is fully hollow, so I doubt the top would be strong enough to support a stoptail. You could easily replace the Bigsby with a trapeze, though. This Bigsby is mounted only at the heel of the guitar, so it wouldn't leave any holes in the top. The trapeze tailpiece will probably have a different mounting hole pattern, so odds are you'd need to fill the original holes with toothpicks and wood glue, and drill new pilot holes for the trapeze. Ideally you'd look for a trapeze that covers the original holes left by the Bigsby. Gretsch makes a very affordable chrome tailpiece, but gold Gretsch tailpieces can be hard to come by. You can always go with a non-Gretsch trapeze, though. One last point: if you don't mind the Bigsby's looks, and you only want to disable it to improve the feel of the guitar, you can just replace the spring with a wooden dowel. That'll disable the Bigsby without requiring any surgery.