Diffraction pads for Wilson Audio Sophia 1

Have owned my Sophia's for 18 years and the diffraction pads have started to deteriorate, can't believe they lasted as long as they have even though they were always covered when not in play. Since retiring and watching my audio budget I was wondering if anyone has any experience with making their own pads and where would I source the material? Now this is not a big thing but if I make and install my own it will save me $400.00 toward the next needed fix in my audio chain. By the way the speakers show as new and sound wonderful and will be in play till they haul me off to the old folks home. Thanks all and enjoy the music