Using PCGS coin price data, neither seem rare but the following appears to be consistent: 79S rev of 78 has quite a premium and somewhat less easy to obtain in 65 and up grades. Even 64 is more difficult. 78 7tf rev of 79 has a somewhat higher premium in 65 up grades. Jim
I used to focus on Morgans & once put together a toned GEM 65 set of the 6 1878’s. Here’s the 79 rev: I can post the others if you would like to see them.