"if something goes wrong in the field, I'm not carrying my set of Brownell's screwdriver bits (good product btw), so I can't use one of the turnscrews in my shooting bag when that happens, and thus can't correct the problem so then I'm .... screwed."
Here's something that I do. I buy odd used allen wrenches at garage sales etc. Grind the short and long arm to the desired thickness' to fit the screws on your gun. They are generally made of some type of tool steel, hard as a rock, no need to harden or temper when you are done IF you don't over heat them when grinding them. They are small enough to fit in your shooting pouch and are darned handy to have in an emergency (change a flint or ?) and cheap, nearly free. Grind the short arm to fit the cock screw slot for maximum torque and the other end for lock screws that don't need so much tightening force.