Notice how the '1' incrementally shifts its location toward the right from N1 to N3.
The N1 is the only variant where the '9' is virtually absent around the '0': both inside or outside of its outline.
Also, depending upon inherent wear patterns
ebay cherrypicking an 1820/19 could prove to be tricky if the variety is an N3 since its vertical part of the '1' appears to be situated somewhat close to the descending portion of the '2'. So always double-check for the outward bulge at seven o'clock on the '0' to avoid missing the boat.
