body panels not lining up

i just recently bought a fender for my car. the old fender had some dents and dings in it and i thought it would be cheaper to replace the fender rather than spending the money to fix the other one. my question is, why doesnt the new fender line up? is there some special way to put these on? i bought a ford one from a car i found in the wrecking yard, and it doesnt line up all that well and nuthing i do will make it fit any better, as it leaves this massive quarter inch fender gap between it and the door. my question is would it be better to buy a brand new one from ford and go that route, or is there anyway u guys can think of to where it will line up better.

see, basically the problem is that the panel isnt sitting flush with the door, and it drives me crazy. most people say dont worry bout it but it really bothers me, and the thing is i am out of adjustment, so could i just make new tabs to put on the frame so i can pull it out further? see if i put the old one on it lines up right but this one just doesnt seem to have the space needed for me to pull it out all the way