Help with dash additions!

I have a Volvo 740 Turbo and I am currently in the process of rebuilding my dash to house a boost gauge, oil gauge, temp and fuel pressure gauge for looks. I have the dash out, drew the designs with autocad, but I've run into a problem from there. I'm sort of new to fiberglassing (which is what Ill be using) and I don't know how to attach the fabricated pods to the dash. Can anybody help me with how to attach the pods?