You might consider trying a mill-end type screw extractor, if you can find one small enough. With those you don't need to drill into the screw, just apply sufficient force for the counter-clockwise oriented blades to get a bite. In that case, I'd probably grab a chunk of thick leather for a cushion and put the Pennys in a vise in order to concentrate on aiming, applying pressure, and twisting the extractor. Theoretically, you could grind down a slightly-too-large extractor to fit, but there you're getting into a lot of work without proper equipment, like a lathe
Example of this type of extractor
Note that if the screw has been made concave, that might actually make it a little easier to apply sufficient PSI. Might.
Example of this type of extractor
Note that if the screw has been made concave, that might actually make it a little easier to apply sufficient PSI. Might.