Try car-part.com.The problem is yards in the area just don't have cars this old. I've been doing some more searching and found spindles on ebay; if i had to piece-meal it, new rotors are $100+ each so I'd end up in the $250-300 range there. I also found a '70 wagon in Ohio an emailed about that.
Pay attention to the shipping cost, too, all this stuff isn't light.Hey I just found a set of '71 Tbird calipers, rotors and spindles for $175 through that car-part.com site. I guess since that's about the same price as piecing it out even with replacing the calipers, it really depends on the shape of the rotors.
I hate to toss good parts, especially if they are original. If they can be confirmed good, turned and still be in spec, what is wrong with that? I stripped everything out of mine, cleaned them, blasted them, painted them, and had them turned for $8 a piece. It was a lot more work, but I didn't buy my car with the understanding that it would be a maintenance-free purchase either. After I added new bearings, races, and seals, they are just as good as new (better since they are painted), and I get to keep another original part.I wouldn't waste my time with used rotors when new ones can be had so cheap. it can be difficult to find places that will turn rotors these days (at least in my area) and the old ones may not have enough meat left for turning. You will need to have them turned for new pads and any stuff this age would be highly suspect, so when it comes to brakes it doesn't make sense to mess round with questionable parts. It is not only your life that on the line.