Victor, you are correct, the '74 has a perforated panel at the top of each of the door / side panels. the remainder of the panel is basically the same, except the older panels had round plastic covers for access to the window motors. be prepared to look for a while, they don't often come up for sale ... especially in great shape. if you are in a hurry, you can buy wood panel blanks from srennoc (a member here). you can either recover them with the vinyl from your existing panels ... or buy vinyl / leather and have an upholsterer make new ones.
you might want to post this in the classified section, with a WTB heading. also i would recommend that you revise your signature to include where you are located