That is clearly a coupe. No rag top. We don't need the whole VIN. Is it a W113.042 or 43?
I disagree. It clearly looks like a lid for the soft top to me. Stick said "It’s a contoured rear bench seat on a convertible, not a cabriolet." I'm not sure what he means by cabriolet with regards to a w113, but he says it's a convertible and it looks to me like a normal soft top lid. And, you can see the release handle peeking out from the seat back.
Also, he said it's a 230.
Were shoulder belts an option on 230SL? This can has them. If not a period option, then perhaps the rear bench with seat belts(!) was installed when the front 3-point belts were installed.
Side note: My Italian spec 230SL, VIN 18381, has original interior and NO seat belts. No holes in carpet where lap belts would be anchored. I will be installing 3-point retractable belts one day.
Also, I have what I believe is a dealer installed custom trim piece on the parcel shelf. Matching leather.