Upload & Sell: On
I bought a 17-35L new about the time yours was made, replacing my old FD 20-35L. I kept it until last year when I bought the 17-40L and 16-35L II. The 17-35 did a lot of decent interior work for me during those years. I found the 17-40 to have more vignetting than the 17-35, but was a little sharper in the center. Both lenses are soft on the edges and corners. I sold the 17-40 and kept the 16-35.
Personally, I'd keep the 17-35, unless you want to get the 16-35 II. Stopped down between f/8 and f/11 will get you the best edge to edge sharpness. Color is very good, and it can be used wide open with decent center sharpness. It is f/2.8 after all!