... Ron Playle puts that AZO two-up-two-down stamp box at 1910-1930, which is a little before PhotoShop, even if people were playing with their negatives long before AZO mixed their first emulsions.
Moreover, the manipulator would have had to do a way-too-extraordinary job to create the calf's leaning-way-back posture, which is appropriate for the slope but darn difficult to fake.
And therein lies the clue. Years ago, WIRED magazine indulged some goofy Apollo Landing denialist, and was treated to two letters to the editor. One explained that anybody with a coupla-joule-per-cm2 laser could bounce that laser off of the polished mirrors the astronauts 'allegedly' left on the moon, the coordinates for which were public knowledge. (Hint: the dusty surface of the rest of the moon is severely diffusive.)
But the more compelling argument was that, with 1960s technology, the mission would have been a lot harder to fake than it would have been to complete
. Astronomers' telescopes, worldwide, showed the capsule, reflecting sunlight, exactly where it was supposed to be, in orbit, in transit, et al, regardless of where, on the surface of the earth, that telescope happened to be. Never mind the radar signals, for which the relevant jammer-repeater technology was decades away.
This photo would have been easier to stage than to fake ...
... but I still can't figger how that calf leaned that ramp up against the roof in the first place.