I would access the condition of your 66 Mustang and use http://www.hagerty.com/apps/QuoteMyC...les/1/Submodel to start negotiating a price.

Would $75-100 be a fair price for a frame with headset and bottom bracket for this make and vintage, assuming that it checks out okay? How about a full bicycle, with vintage era parts... would $150-200 be fair (assuming it was fully re-greased and tuned)?