Turbo Rocket-Oldsmobile COPO?

[The Dude]

Explain the process of how they took a convertible body and welded on a Buick roof. It doesnt make sense to me, but I dont know much about these cars. What I do know is GM quarter panels extend to the top of the C pillar with roof skins welded over the inner roof structure. Everything was welded together on a jig. Why would Olds weld together a complete vert body THEN add a roof? Id think Fisher body already had the capacity to build the car, so why was it removed from the regular line to add a roof? Im just trying to understand the process, thanks.