Welcome to the forum
I'd say you did good on the price for what you got.
Not to pee in your wheaties but have you checked the VIN on the cab and frame to be sure it matches your title? Reason I ask is that I see they used a e-brake crossmember for the trans crossmember. That style of e-brake crossmember was used '63-'65 and not in '66. But it could be just they used what they had. I would still check it out if you haven't already.