Hello
I don't know what you mean by "double edge lettering inverted".
I would go to the link shown below. It is a listing of the
coin population report. At the lower left of the web page
will see the following list.
Flowing Hair Dollar (1794-1795)
Draped Bust Dollar (1795-1804)
Liberty Seated Dollar (1836-1873)
Trade Dollar (1873-1885)
Morgan Dollar (1878-1921)
Peace Dollar (1921-1935)
Ike Dollar (1971-1978)
Susan B. Anthony Dollar (1979-1999)
Sacagawea Dollar (2000 to Date)
Presidential Dollar (2007 to Date)
Base on the above information, the Adams Presidential
dollar coin you have, may be listed in the population
report. It order to know that the coin you have is listed
you will need to submit the bar code information. That will
require your membership information to get it on-line.
Otherwise, you will have to E-MAIL them, or call them
direct.
.
It means that the coin was run thru the edge lettering machine twice,
once heads up and again tails up.