They are a nice set to put together and underrated. I have a few but not a set at all. But I did see a proof set of them once and it was gorgeous.
I really like the proofs. Only a few thousand made for most years. Always thought these to be a bargain.
I saw a complete set of them in MS grades. At least they looked MS under the glass. The set was $13,000 several years ago. It was a beauty and I think the 85 and 86 were certainly 64's. The local dealer put it together in the 70's and had just bought it back from the guy he put it together for. The only complete problem I had with it was it was in a capital holder.