Colnago Carbitubo, twin tube, STI shifter, & Dura-ace

This frame is made out of carbon tubes which were developed in cooperation between Colnago and Ferrari and aluminium lugs by Alan. In 1992 it was one of the first Generation carbon frames of all the time. I have been the only owner of this bike. It was bought in Italy. This bike was ridden by the italian National team in the 1992 olympics and won silver medal in TT distance. I am thinking of selling it because I rarely ride it anymore but have no idea of it's value?