I am totally thread necromancing this, just for posterity and in case anyone cares about this still.
So, I am in the process of listing a
DMG for sale and in the process of trying to determine it's printing, I see that it matches none of the listed printings on the site currently.
https://www.acaeum.com/ddindexes/setpages/dmg.htmlFrom what I can tell, the DMG that I am listing now runs somewhere in the sixth printings, however it also has a couple of key differences that are not currently enumerate in any of the one currently lisited on the site. This copy is closest to the listed Sixth gamma, via:
"Sixth Gamma (1980)
Endpapers and flyleaves are white
The text on the spine is aligned to the "bottom" of the spine, rather than being centered. This is possibly due to the printer using a slightly thinner cover and/or page stock, resulting in a thinner overall book
No survey form, and reference sheets are NOT perforated
236 numbered pages
This print is otherwise identical to the Sixth Alpha print, above"
However, while my copy has white endpapers and flyleafs and only has "Advanced D&D*tm*" on the front cover(with no adventure games as listed on the 7th print), the text on the spine is centered(as opposed to near the bottom), it has 238 numbered pages(not 236), it has no survey form and while the reference pages say that they are perforated, they are most certainly not. They are bound like regular pages and no signs of any perforations on any of them.
Based on these differences, I suspect this would put my printing slightly later than the sixth gamma, but before the listed seventh print.
ETA: I just took a bunch of pictures too, just in case anyone wants to see them.
"He who fights with monsters might take care lest he thereby become a monster. And if you gaze for long into an abyss, the abyss gazes also into you." -Neitzche