I've done a lot of door handle modifications over the years. I put a set of Dakota handles in my 48 Plymouth coupe that I think I still have pictures of, but I'm pretty sure it won't help much with the Cuda handles in an A body, other then maybe a process. Every time I've done a door handle swap, brings its own set of modifications, some transfer, some don't.

Pretty much, you cut the sheet metal around the new handle, and align it with the sheet metal of the old handle. Then you cut the old handle sheet metal out, and weld in the new sheet metal. After the outer handle is done, you may need to cut the section of the door latch out and do the same with it. After all the cutting and welding is done, you get to modify the inside linkage, the outside linkage, and the outer door lock linkage so they all function. Then you get to do body work over your welds and patches. Quite a lot of work to install poorer quality Cuda door handles in an A body. Gene