Internal gust locks were very common on older types...DC4's, DC6's DC7's, Stratocruisers, F.27's, etc.
A large cockpit handle was moved to lock the controls in the neutral (usually) position while parked.
Of course, as with any cockpit device, there invariably comes a time when someone wonders...what would happen if I used this in flight?
The crew of a DC4 found out many years ago just west of KELP when a crew member (actually a check pilot in the obs seat) applied the gust lock in flight.
IIRC, the aircraft was unrepairable due to the twist in the wing and horizontal stabilizer.