I'm not trying to discourage you but by the time you make your own masters and then take molds from them you will easily reach the costs these guys are asking for panels. I wish someone made panels for chevelles when I stared on mine, I may have saved money . Unless you get it perfect the first time there will be wasted materials and alot of trial and error. I have too much invested to turn around now. This may help your decision.
https://lateral-g.net/forums/showthread.php4?t=10123