Hey guys, let's keep this one quiet until I'm done with building this set!
I started this set a couple of years ago and it's about 65% complete with all cards PSA 6 or better. I agree with all of the previous comments. It's been a blast and surprisingly affordable to build thus far. The Redskins and Cardinals players are SP's, but I have found that the Redskins players seem to be slightly tougher than the Cardinals players. The #1 Carson still eludes me, but I have a lead to pick one of those up.
There is a really nice selection of HOF rookies in the set like Lenny Moore and Rosey Brown among others, but it doesn't quite have the iconic star power that it's younger brother ('57) has with Unitas, Starr, Hornung, and Berry. With no iconic RC's, the interest in the set as a whole has been relatively tame from what I've seen over the past couple of years. I also feel that it's slightly undervalued, much like the majority of the vintage football market as a whole.
Best of luck on the set!