Have an 80 Avanti with a Skytop. It leaked and didn't work so the po silicone sealed it shut. For now at least I'm just going to leave it, but it has no inside slider --that aluminum panel you can slide from back to front to shade the sun. Can anyone out there provide me with the exact dimensions of one ? There machine shop said he'll make me one but don't want to guess on the dimensions. Thanks!