stuck doors!!

Help. My door on my 73 duster inst opening. The door is unlocked. The button goes down on the exterior and i can see the parts moving on the inside but the latch wont budge. Help.
Mine were rusted shut. What I all the mechanism that keeps the door shut. I had soaked with penetrant several days and hit it hard with long punch and big hamer! I finlly gotit working with th air chesel an somegood pounding. Once free it moves and works great!!
The second dorr was same xcepththe lock was also rusted shut and almost catching th gear to lock it. It as just up against the mechanism and that mechanism was also rusted shut. The window regulators are also rusted and not moving!!!
This is a Tx car, NOT on the coast and sat with all windows up!! But had sat sine 1980!!!! LOL
I probably would have never got it unstuck without that air chisel, my torch was down and that could have easily got it loose. But..