I've been working on my mame cab for a bit now, and it's come time to finally paint her with a couple coats of Melamine semi-gloss. The last bit I need to take off the cab was the black grill covering the speaker panel. While trying to do that this morning, I noticed that the screws used to hold it in place were oddly shaped. They're mostly like a standard screw that takes a star-shaped bit, but they've also have a spindle of metal sticking straight up in the center of the bit hole. From the looks of it it seems like you would need a star-shaped screwdriver that has a hole in the very tip to accomodate the metal spindle.
Has anywhere ever seen these types of screws before and know what they're exact name is? And if so, what type of screwdriver would I need to remove them? My cab is an original Midway MKII cab, so perhaps it was a custom bit only used by Midway or the arcade industry in general.
I've inlcluded a pic below so you can see a cutaway profile of the bit hole and on overhead shot of the overall shape:
