I shared this post on another forum before joining here, but I figured I would post it here as well since I have the final product in hand. This was my first time cherry-picking my own collection. The second cherry-pick was the 1797 proof Soho Penny I posted about earlier. When I purchased this coin, I did a very surface-level examination to figure out its relative value. In my haste, I correctly identified the obverse as 2 (as distinguished by the toothed border and the position of the signature in relation to the border). I also managed to correctly identify the reverse as D (as distinguished by the toothed border, position of the signature, and thin shield lines). I assumed this was the more common 2-D pairing, and I wrote it off as a decent example of a common coin. After closer inspection, I realized that this coin is the N over Z variety. The price difference between the two is substantial. The common 2-D in Spink (2018), starts at 3 pounds in fine condition and jumps to 350 pounds in BU. The N over Z variety lists at 90 pounds in fine and jumps to 1,850 pounds in BU. Key characteristics include the A over V on the obverse, the re-touched “O” and tail like bit under the left foot of the N in ONE. Pictures are below, including closeups of the critical characteristics pointed out above. My images: I had some issues getting the variety listed on the holder (mechanical error), but as always, NGC customer service fixed the problem. Here is the final result in the slab. These are the cert verification images (edited to remove the cert number and barcode).
