Take a picture of all the panels you're putting art on, from as straight on as possible.
Measure every edge, every angle, everything.
Open your picture in photoshop, take the measurements you took and on it's own layer, draw lines to those measurements, tracing the shape of your photo. The perspective of your photo will mess with you, but if you have taken the right measurements and angles, you should be able to re-build the profile within photoshop as a template.