Trying tp put the pieces together on this puzzle. I have a 71 cuda that had a bench seat and want to put buckets in. I have bucket seat frames that have a chrome button on the side to release the backs. Are these correct ? I also have a set of the cast covers that i know fit the 70 cuda. These seats came with the plastic backs that cover the hinge. Im a bit confused as to what parts are the ones I need. Thanks