Don't know what to say... I have a 1st, 2nd and 3rd print and all have the same "copy" shown in the pic. The first pic definitely indicates a 1st-3rd print, the telling info is lacking. Namely the copy NOT shown in the title page pic. At the bottom below where the pic cuts off, if there is no printing indication; it's a first. If it says 2nd printing, September 1978, self-explanatory, same goes for the 3rd 1979 printing. Without seeing that I cannot make a decisive call.
PS I am sure you know this, but the
DMG is obviously nowhere near a first print.