These are not metric screws, they are English/imperial.

The drop target screw is a 1/4 inch, not sure about the other one.

Where you are located? If you are going to work on US machines, order an English Allen wench set and a couple of common nut drivers.

You can use metric in a pinch, but to get the flipper tight enough to hold, you may strip the Allen heads with a metric tool.

Well if you are going to work on it, you'll need the tools above at a minimum. A crescent wrench (what we call adjustable here) won't work in a lot of spots on the machine.

GL.