Torx is only a starting point. A 12 point flange, a double hex, or spline drive would look fine on that floor plate screw and would not draw your eye like a slot, even a brand new clean slot.

The problem with screws, is that they fit exactly once. They work by being stretched, and the final position after reassembly and proper torque is different. You want a fastener full of Locktite just so it looks 'proper'?

I realize these designs were finalized in 1875, but a slotted screw is simply not 'best' in 2017.

Fire away!

"The price of good shotgunnery is constant practice" - Fred Kimble