AMD fitment for 68 fastback

So.. The time has come to start on some bodywork on my 68 barracuda fastback. I plan to have the passenger side quarter panel, entire trunk floor, and trunk extensions replaced. Auto Metal Direct lists trunk extensions and a quarter panel for the 68 Cuda but no trunk floor specific to the pre 1970 A-bodies. What sort of fitment issues do you think I will run into as far as using the trunk floor listed for a '70 dart for example?

Anything else I should look out for as we attempt to do a job of this size?
Thanks so much. :)