The bear claws are the only SAFE way to go. My '31 Brookville came with the OEM style '28 - '32(at least) latches that could open if the body flexe - and being a roadster, can assure you that it will. Since the doors have only about an inch of space, could only use the single rotor version, I opted to install safety pins as well.

You can see the bear claw and the safety pin here - also some of the reinforcing steel added to minimize the body flex as well. It also shows a door latch solenoid that currently isn't wired, but there for a future mod