I used cardboard to make the template, then cut my panels from 1/4" playwood, screwed a 1 x 4 on the top (ripped to the proper width & notched ends) to make ledge & cover the bolts that hold the top on. After they were fitted perfect and notched perfect along the top, I wrapped them in carpet, and for the final touch I added some lights & speakers.
These pic's are from a 77', which has a different rear drivers side because of the gas tanks.
My expericne has been that they're all a little different and its best to make a pattern for each one.