Hello,
We appreciate your enthusiasm for the Panama coins and registry sets. Our Senior team considers sets on a case-by-case basis and has determined this set structure is better suited for a Custom Registry set.
This 1978 10 Balboas coin is the only coin minted in Nickel Mint State and not Silver proof. This is a one-off coin and is not eligible for a competitive registry set. If you wish to showcase all the Silver Proof 10 Balboas and this Nickel Mint State 10 Balboas coins, you will need to create a Custom Registry set.
Ultimately, the placement of coins in the competitive NGC Registry is determined by our Senior Numismatic team. Thank you.