Numista and Krause catalogues do not mention any double mintmarks for this number. I actually have 2 coins for 1922 where the mintmark appears to be F over G. The diameter and weight of the aluminum coin match the figures given in Numista. https://en.numista.com/catalogue/pieces2729.html
http://www.coinquest.com/cgi-bin/cq/coins?main_coin=755 has some claims by other collectors for this variety for other years. My coins also look to be double die errors. Has anyone else seen such varieties? Should it be considered genuine? I assume they are not worth much of a premium. Thanks for any comments.
Looks more like a stylized F to me here is another one. Maybe it's from one of the first dies were they were experimenting or had the time to do extravagant things and had to simplify it on later dies?
I think you may be right, Idolenz. That may be the case as this situation does not seem to be rare. The F mintmarks I have for other years are not very sharp, 1920 is badly blurred and 1921 somewhat matches 1922, looks like it could have been cleaned up from more stylistic die. Thanks for replying.