I am sifting through all the early 1960-1964 Proof Sets I bought over the past few months and have another coin that would probably render a minor DDO
The only area I see any doubling is on the E PLURIBUS UNUM. Tonight, lighting was giving me issues, so I took the easy way out and set the magnification to high



















I don't know what this is below Jefferson's Neck, but it looked odd;




It surely looks like a DDR, but the way the metal was flowing around that rim, I am thinking it has the possibility of being some sort of weird die ejection doubling / machine doubling. If I had to make the call, it would be to the side of the DDR