As is Lo chiamavano King which Bruckner gives us with 96 min.
I find that more than a little unbelievable. For starters, it doesn't feel like there's anything missing. And it's already padded up with a whole lot of stock footage. Why cut 20 minutes of a cheap B-western? Seems to defy logic to make a movie on the cheap (very cheap, that is), only to cut about 1 fourth of it afterwards.
As for Bruckner, I've never read the book but I think we shouldn't take any book or database as a holy bible for running lenght or any other information I sometimes wonder if certain given running lengths are for all footage shot before editing (work prints).
And what is supposed to be the definitive print? The Italian one? German print of Seven Hours of Gunfire only runs 73 minutes (yes, another shortest spaghetti contender), but they changed just about everything in the dialogue, even lead character names. Plus it has a ten minute intro that's missing from the Italian print shown on Australian SBS TV. That same Italian print is also missing a long saloon scene (7 minutes) present in the Spanish version.
All footage taken together will probably yield a 100+ minute movie. But was it ever intented that way? This was a Spanish/Italian/German co-production, and it seems they made a different version for each country. So it's clear the IMDB runtime of 76 minutes (24fps) only takes count of the German version. Granted, IMDB isn't much of a reliable database anyway...
A few more shorties:
watch out gringo (83)
ballad for a bounty hunter (83)
ride and kill (82)
woman for ringo (81)
fury of the apaches (80)
5,000 dollars on one ace (79)
la belva (77? could be cut)
outlaw of red river (74)