Any easier way to file bed wear strips holes square

[72step]

So I made some good progress over the weekend and milled all my composite trex board for my 65 C10 stepside. I put it together as a mock up to test fit the width and by luck exactly 9 of the 5.25" boards fit perfect. So regarding the strips I didn't get the kit because I needed more than 7 and little did I know that if you order them as separates from LMC they don't come drilled so it's going to be a real PITA to drill and file 56 holes especially to file by hand. I did it on the angle strip covers but man it is time consuming and tedious. Any ideas to make this easier on me? A friend offered to loan me an air file. I've never used one so I don't know if it would work. Perhaps a dremel? I've never had one but I'm just trying to think. The only thing I can think of is to try and find button head bolts with an allen head or torx. I think that would be quite expensive and might not look right. Any ideas? Thanks.....Matt