I'm not sure what constitutes an original source for a photograph. I don't have any idea how many times it's been, but the 2 best sources for the photo are p. 104 of Lawrence Frost's "the Custer Album," and p. 78 of Mark Katz' "Custer in Photographs." Katz system for IDing Custer photographs lists it as K - 94. The photo is in the collection of the Little Bighorn National Monument.
I think the Katz version is the best print and contains the a handwritten identification by a person unknown of "Custer," his Sibley tent," the "Indian Scouts," his "Pelican," and a smudged
"_dqrs flag."
I would be surprised if West Point didn't have the "Custer Album."
I haven't checked but used copies might be available on Amazon for less than the price of shipping. "Custer in Photographs," is probably more expensive, but except for 1st editions, it might be reasonable.
I haven't had a chance to search on line, and if I had the ability to post the photo here, I would have done so by now.