This is a replacement glass for the tail light of a veteran tractor (in my case a Volvo 320, but I think it might fit some other tractors as well). The glass fits in a tin cup with an inner diameter of 55 mm and is designed to be a press fit. I assume it can  be scaled to fit other similar armatures.

Print in translucent red PLA or PETG with flat side down. If desired the part that fits inside the armature can be printed in a different, non-translucent color.