ran across this photo of a very original coupe ... and i think you can see the gasket under the trunk roundel. it looks like the lip goes under the roundel base
When the item being used over a flat rubber gasket, depending on the thickness, is tightened up, it will draw ino the rubber and look like it has a lip around the edge,
The two piece is from Rogers tii (I think)I'm in for one also.
I came back fro my last drive this week sans rear Roundel. I have not looked yet, but are the correct raised letter roundels still available?