Rep Power: 425

Last fall I built an aluminum panel to mount my gauges in. For whatever reason, I want to re do it. It matches, but I just don't like it. It just doesn't look clean to me anymore. Anywho... I want to redo it in black "something" so it matches the dash and just the gauge bezels have the aluminum color. I want to put them in the same lower panel where the 2 accessory buttons and the cig lighter should be, but I want them flush mounted to the dash, rather than stuck out on angle rings like they are now. What I want to do is fill in the recess in the panel so its flush all the way across, then get 2 holes in it so I can mount the gauges, but have them tilted up and towards me, just like they are now.
I had the thought of just leaving the panel there, and filling in over it with something, but I'm not really sure what to fill it in with, nor am I sure it will work without cracking around the seam where it meets the plastic panel. I know some of you have rigged up VAFCs to fit in there, what did you make your mounting faces out of?
Thoughts would be to buy a plastic sheet, cut and sand it to fit, then use plastic filler around the edges. Second would be to fill it with fiberglass, but I have no idea how the hell to mess with fiberglass, 3rd and probably stupidest would just be to bondo it up.
I'm really not sure how best to do it... all I know is I don't want to do it 3 times. It needs to be something paintable so I can paint it to match the dash color when its done too. Ideas? Suggestions? Options? My current gauge face is in my gallery thing.

 
Rep Power: 332

your best bet would be to use a sheet of plastic. you could just cut out that portion and make a stencil and just cut out the shape from the abs plastic.