The best thing to do to price a sofa like this , would be go to any local Antique Shops , see what the prices they are getting for a sofa like the one you have. Then you can take off any deductions you think should come off for condition of your piece. This gives you the best idea of what items such as these are selling for in your area. I would also run an ad in a local paper, and check with any resale shops in the area that do consignments, dealers love to pick up pieces they can put a little work in and make a little money. You might also consider running it in a local auction.
Hope this gives you some idea of how best to sell your sofa.