Nah I'm trying to figure out how to put the groove around the outside which is then removed through the center giving those 2 lips that extrude on the top and bottom, I was just looking at the overall thickness of the part and thinking maybe it's not right as a separate issue of ID'ing his part in the first place. Maybe they took this and sanded like your saying to make it thinner but that seems like a lot of work, usually these answers are easier than that when tracking these parts down.
The part circled in green is just showing how that inner lip matches on the 2 parts in an attempt to make a positive ID on this part in the first place.
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I think I'll just 3D model and print this dish haha be a lot easier then bash all the pieces onto it...