1967 convertible rear seat

Looking for the width dimensions of a 1967 mustang convertible rear bench seat vs. the coupe rear seat model. I have a seat that I'm getting ready to sell but want to make sure its a convertible like I was told, so I need the width dimensions of the two models to confirm.
thanks

Best I could come up with is interior space dimensions. The coupe hip room lists at 50.8" and vert 43.2". Then the coupe shoulder room at 53.6" and vert 43.2". You might be able to take your measurements and base your decision off of that.