Help - Monster Tach Dash Installation Goof - I am an idiot

Sometimes I am as dumb as a bag of hammers....

I bought an Autometer 5 inch monster Tach with shift light to install on the dash of my 1971 Dart Swinger with new interior no less.

Tested many locations and due to the shift light and narrow dash and window angle I had to screw the bracket close to the edge of the dash.

I just assumed that the dash was wood surrounded by cover like my Challenger or foam around wood. Nope.....just pure foam. :banghead:

So I screwed in two screws hoping to hit something secure but got nothing. :banghead:

The bracket is in but it will never hold for long. Beautiful dash and I don't want to keep drilling holes in it. Any ideas how I can fix this using same area where the holes are now?