Well what you have in that picture is a metal panel that screws in that’s black and they have made a insert inside the raised groove in the metal. You should use a piece of 1/8 abs cut inside to fit the raised groove and wrap I wouldn’t use anything thick or won’t look right when door was opened
Sorry I'm slow to answer, thanks Clinton that's a good point on keeping it thin. My customer supplied the metal insert, so it should be a straightforward job! Appreciate everyone's advice!