On Tue, 20 May 2014 11:12:00 -0700 (PDT), True North wrote:

I was hoping we could maybe use the next size bigger self tappin screw, otherwise it might be a chore removing the the inner panels to get to the bottom of the gunnels in order to use a bolt and nut faster.

Nope, bad idea. Fill the holes and put straps on the cover - or buy one with the straps.