http://www.marcospecialties.com/pinball-parts/PI-3121-KYT
There you go and your all wrong it's kidney shaped!![]()
Sorry Dave but I don't agree with ya - I think it's a Oval insert as per the hole in the playfield - like this http://www.marcospecialties.com/pinball-parts/PI-251634-ORT
The topside is painted into the kidney shape, confirmed by the underneath picture.