Here's the test I did with the 3 piece Excel pounce wheel set on a piece scrap styrene (old Monogram F-16 part) from the 'boneyard'.
The top row was done with the same tool as the second row, I just wasn't pressing hard enough to get the wheel to dig in. The bottom three rows are done with the 3 different wheels, hence the different spacing.
As you can see the holes have corners so you would have to follow up with drill be to make them round. The picture is taken very close up with the super macro setting on the camera. So at actual size with a Mark 1 eyeball one would be challenged to notice the holes are squarish.
I didn't think of it at the time but I could have put and 1/4" architects scale by the picture so you could have an idea of diameter of the holes in 1:48 scale. But based off some back of the napkin calculations I would estimate the holes are about 3/4" in scale diameter.