Garmin GPS Antenna Mount Question

[UnPossible]

Hey - I am trying to install the GPS antennea for Garmin's G3X system. Before Garmin's big price reduction, I had been planning on using Dynon's Skyview and had drilled the holes in the top turtle deck for their GPS antennea. (Note - canopy will be a tip-up)

As you can see in the picture below, the top two holes for both antenneas match, however, the Garmin antennea is a bit longer. Unfortunately, one of the holes required for the Garmin will remove about 1/2 of a rivet. Would it be acceptable for me to drill out the rivet, drill the new hole where indicated, install a nut plate, then fill what's left of the rivet hole with epoxy and flox?

Is there a better solution, or do I need to move this forward a bit and drill all new holes?

Thanks for any suggestions,
Jason