Afraid you're wrong. Professionally speaking, as part of my work I've commissioned photos and forensic photo analysis as part of investigative research for a number of governments around the world. Take a look at the attached. This isn't poorly exposed; the forward part of the gun does not exist in this photograph, I can assure you. Any expert will tell you the same.
In a fraud case e.g., this kind of photo would lead to a police interview, at the least.
Okay, so it's not there so has been removed from the photo for some purpose. The point being is that we don't know what that purpose was. There may have been some perfectly legitimate reason to do it, either evidential or technical? I do not know what that may be though. Indeed, any perfectly reasonable explanation at the time may have been lost in the mists of time.
One cannot simply arrive at the conclusion that it was done as some form of conspiracy or cover-up attempt. There is no evidence to support that. Even if it was then it's a pretty amateurish attempt, quite frankly.
It was not done to disguise the type of weapon as it's very obviously a GP-35
It was not done to make it look like a different variant of the pattern as there are none.
There is no story associated with the "short" weapon that anyone has put out that would require a shorter gun to have been used.
There are no claimed "facts" associated to the case in any respect what-so-ever which would require that photo to be doctored in that specific fashion.
We are also forgetting that we don't actually know the full history of any of these photos or of their reproductions posted on any website which has them. They were taken twenty six years ago, almost certainly on 35mm film, in a dimly lit hotel room at night and many will be copies of copies some of which may have had any amount of alteration done to them for many legitimate purposes. The two websites linked to below have the "same" photo on them but they look very different indeed. One is much brighter and clearer than the other. So there are already perfectly legitimate differences depending on where you look.
The Oslo Plaza Hotel Mystery - who was Jennifer Fairgate?
Who Killed Jennifer Fairgate? - Reddit Theories on the Oslo Hotel
I don't think it can be stated with certainty what a picture actually shows or doesn't show unless you have access to the original negative, a first generation print made from same or the digital file as it came off the camera which took it. How do we know that every copy of that picture on the internet didn't actually originate from a badly exposed photograph of an original printed photo which has managed to obliterate a part of the picture perfectly innocently? We don't but that is a perfectly plausible explanation. Indeed, we don't know the true origin of any of the photos of this event; yes, they were original police evidence photos but we don't know where the ones we find online actually came from. Even the good quality ones of the gun taken in a properly lit evidence photo room are (from memory) photos of actual printed photos taken at some point in the previous two and a half decades so it is not unreasonable to consider that that may well be the case for every one of the other photos.
I'm at a loss as to how you can analyse something for evidential purposes if you do not know it's true origin. If it is a copy of a copy then you are analysing the attributes of a copy of a copy rather than of the original.
If people want to spin it as evidence of some sort of conspiracy or state cover-up then that's fine but they need to provide evidence for that and a picture which simply doesn't look right is not evidence of anything other than a picture which doesn't look right. The problem we now have is that a lot of people are in "conspiracy mode" and it's clear from the tone of some of the posts that people are "investigating" it from the mindset of it being evidence of a conspiracy and are looking for additional evidence to support that pre-conceived idea. People are reaching the point where they
want there to be conspiracy. If not so much on here some of the more radical conspiracy theorists out there will definitely fan the flames over the internet. That's rather depressing and sad because every rational way of explaining this ends up at the conclusion that a lonely young woman decided, for whatever reason, to end her life alone and unloved in a hotel. I'm sure there will be other factors surrounding her death as I suspect that there is likely some criminal or underworld connections but I doubt it'll be anything particularly unusual. It
might, might be a badly investigated murder but I think that suicide is by far the more likely explanation.