I want an inside Hood Release in my '71 Duster. Can't find -'71- only '72-'76. Will they work?

You're looking at a cable and a latch. You will need to get it from a later model car that used inside releases and figure out how to mount the control inside, string the cable, and modify the latch mounting if needed. I bet the latch mounts like yours does with just 2 bolts. Like your hood latch, I mounted a electric trunk latch from a later model Mopar, on my 70 Swinger and wired it with a remote control and key fob. It was easy and works great. The late model latch replaced my manual latch without modifications and the manual key release still works.