Replacing the fender is easy, but time consuming. Double that time if you are removing a fender from a junkyard car. I've done it on my 245 and it turned out perfect, but the front filler panel had been spot welded at some time and had to be cut & ground out. As for a salvage title, from a past experience, it's a royal pain. In Ohio the State Highway Patrol must do the inspection and it's at their convience not yours. This means taking time off work to drive there. Ours is 40 miles away and not open on weekends either. They also demand a parts list with serial numbers from the junkyard car(s) you got the parts from. If the serial # is from a non existant or stolen car, BIG TROUBLE. This will only get you a "rebuilt-salvage" title which is a red flag for any future resale or trade-in.
I had a rear-ended $50 Ford Crown Vic from a friend that cost me over $500 to get back on the road. Only got $425 for it when I sold it, and it was nice too. The blue book was about $2000.
Ben