Contact John Thompson on the site as he was a builder at Trek during those years. He could also probably tell you who built that frame. I believe theres another member or two who also worked at Trek during those years that are active on the site. He used to be local to me when I lived in Wisconsin and referred me to Doug when I inquired about my interest in taking a framebuilding course.

As for the additions you want to add to your frame. Why the front derailleur tab? I found these to be restricting on chainring sizes, choice of derailleurs. I added one onto the 3rd frame I built and absolutely regretted it. I changed cranks to ones with rings sized to something found on a cyclocross bike which I find more usable and couldnt lower the derailleur enough to work with that setup. I would honestly spark up my torch and remove the tab but since it was powder coated removing the coating is such a hassle I hung the frame up years ago and haven't touched it since.