FWIW, I have an 83 Trek 700 that I bought several years ago. The profile pic is similar.



As purchased 83 Trek 700


This fork looks nearly the same as the subject bicycle. I was concerned also and put a straight edge alongside the headtube to have a reference point. It seemed fine, and perhaps the 79 may also be. I my pic, and the subject pic, the off side fork leg because of the camera angle appears to be behind the drive side leg. It does give the impression of both legs being bent back.

My fork and subject fork have a curve that seems to begin further up the fork leg and with a more gentle taper. I think that adds to the optical impression also. I’m not saying the fork isn’t bent, but there are optical factors too. Mine rides nice with the full 531, so the OP might miss out. Perhaps taking a straight edge along while checking out that bike would reveal things.