My father bought it used for his architectural business and then stored it in his basement for 40 years. When we brought it up out of the basement it fell apart so we had it restored. The man who restored it estimated that it was circa 1850 and said he had an offer of $5000 for it in 1993. We recently gave it to our son and would like to give him an idea of what it is worth.
The desk has been kept in the house since restoration and is in excellent shape now. The wood is beautiful and there are few scratches except for a large one on the roll top from a loose screw at some point. We think this gives it character but we're not appraisers.
Please see photos below. I can supply more photos if needed.