Put a small piece of tape (not real tight) behind each hole and slightly over-fill with J-B Weld. Next day, file & sand till flush, wipe with tack cloth, and spray with a "filling" primer, which is usually pretty thick stuff. If you wind up with a "ring" that can't be camouflaged by the primer, try using a gap filling cyno-acrylic like Slo Zap. I used to get Slo Zap at a great old school hobby shop in town.