IDK what kind of wood working tools you have on hand, but some router work might be nice & considering all the effort to make the mount be wood for the eye to see, Im kinda surprised you didnt set the ends of the bolts deep enough to run plugs into those holes & cover the bolts up. To my eye, the mount is just too bulky ( dare I say "blocky"?) on such a small built bike & a smaller mount, generally, would have been more eye appealing, BUT, all that said, that is some solid work & the thing is, how YOU feel when you look at it & you know you solved your problems in a way that makes you happy. I would have leaned toward some skeletonized aluminum bracket, trying to make it the smallest part I could build that would have held the GPS &, I guess, thats a 12 volt plug?