DANG, Runar! Keep a couple of the pictures, maybe enlarged, and post each one with a label "This Is What Happens When a Gun is Not Cleaned and Lubricated AT LEAST Once per Year!"
Looked at that one near the bottom, the trigger guard. It looks as though it is time to brush it before the next step in bluing or browning. I have a very fine wire wheel that does that carding very nicely.
So, card off all the rust, put on some bluing or browning solution, then go through the cycle a few times. When you get it done nicely, boil it and make it black - then give it back to the owner.
Looks as though it was once a very nice firearm that would shoot straight.