If it were me, I would simply cut out some circles out of heavy yard sale signs at home depot in the correct diameter of the circles on your part, then clamp the vinyl sheet to plywood. make a center line on each part to line up your circles, and then with an exacto blade just trace around the circles to deeply score the panels, then cut your longitudinal lines carefully, pop out the panels, and touch any burrs up with sandpaper. This may not be the 21st century way of doing it, but I think you will have a great part after the second or third time of practice and you will be able to mass produce these using your circle patterns. hope this help you in any way.