Making a tube spacer and 5mm threaded rod to extend the dash mount points should be easy, although I don't know if it will vibrate.
West Systems, Black 5200 glue is a good match to fix the rubberized dash, and you may find something that matches the pebbly surface pattern. Oftentimes, your SO or wife's favorite pair of pumps works well, and cutting out a section does the job. Hint, WS 5200 takes about a WEEK to cure! Yikes. Have fun.