Suggestions for building a dash panel

[G-Rex]

Ok, so....against my better judgement, I'm going to solicit y'all for suggestions. I'll preface by saying there is NO room behind the dash, or under the existing fairings in places where they are easily accessible.

I want to add two knobs for my Gerbings heated gear, a volt gauge, and two accessory switches for, um, stuff.

I'm considering an ABS plastic dash panel of sorts. What I envision is similar to the cardboard mockup in the photos. I'm going to want the unit to be enclosed and water resistant. I will need one opening for the wire harness to run through but that's not my concern right now.

The cardboard piece I mocked up obviously doesn't have a bottom or back on it, but the face and top, are generally what I'm looking for. I'd *like* to follow the contours of the dash panel as best as possible. Average dimensions are 9" wide, 2-1/4" tall, and 1-3/4" deep.

What I'm looking for is feedback on how in the hell I can form a piece of ABS to make what I want, suggestions for other material, or just any other idea in general to get to where I want.