are you an upholsterer? headliners are not something the average rodder should tackle, it takes years of practice on a comercial machine to produce an acceptable headliner, they may look simple but they aren't. J.C.Whitney has a very good supplier of reasonably priced headliners in both cloth and vinyl,(cloth is easier for the novice)they have patterns for virtually everything, even my 37 terraplane. do it right call them.
u will get the measurements by measuring the listing wires attached to the roofline,but even a pro trimmer wouldn't tackle a headliner without a pattern!u must have the listing wires or your screwed!and keep them in order of install.better yet,follow previous advice!!