I think the dash would look like a nice clean install if you used body panel glue and glued it in place. Or bolts welded to the back side of the peak piece and oval holes in the original dash for adjustment. Just a thought.
Were on the same page here, thats one of the reasons I had Peak Dashes not pre-drill any mounting holes the other was alignment limitations...I'm thinking welding stud's to the back side to keep everything hidden and clean.