Thanks for all the info everyone, it slipped my mind that I could ebay search for 750 switches specifically as well. @messeduptriple, I'll buy yours off you, pm me how much you want and we can set something up.
My bike is a '75 and I'm 95% sure that's what year the control is (no reason not to be, but you never know), however, I'm not sure how just a button and a spring would make it work as right now there are two wires coming out of the button's original hole to the aftermarket button on my handlebar. I'd assume I need something for these wires to screw into so that when the button is pushed they contact. More of a complete switch assembly than just a button face. If someone knows the inside of the unit better than I do (maybe there's a place where these wires screw into the inside of the housing or something?), please explain.
In looking through the microfiche's (plural?) I can't find an exploded view to figure this out myself. Also, useful info, my horn button does not have the letters "tec" stamped on it where you press the button (as I learned from an ebay listing) and something about these types of buttons won't work with a housing where the button wasn't stamped with this. The listing explains this specific button was on '74 550k's
So yeah, assuming I need a switch now not a "button"?