What's desperate is you trying to pile an envelope onto your supposed "mountain" that cannot be connected to any particular Klein's order or any particular weapon.
The point is that if the probability that each of two independent events occurred is x, the probability that both events occurred is x
2. And since x is always less than 1, the probability of all events actually occurring keeps going down exponentially as the number of events increases. You do not seem to appreciate this.
So you have a doubt that Oswald filled out the Klein's coupon and the envelope with his Dallas post box, even though it appears very similar to his handwriting and to the handwriting on the coupon he filled out to purchase the handgun that Marina herself as Oswald's. Then you say you have a doubt that Klein's filled that order at all, despite the shipping order that was prepared showing that C2766 was used to fill the order. Then you say that you doubt that Oswald or anyone took out a money order to pay for this order. Let's say that the probability of each doubts being fulfilled is x = .1 (I am being generous: that would mean that, contrary to their documents, 1 in 10 of Klein's orders were not ordered; a 1 in 10 chance that items were not shipped; and a 1 in 10 chance that they would indicate that an order had been paid when payment had not been received).
In order for Oswald not to have received the gun, all three doubts must be fulfilled. The probability of fulfilling all three doubts (i.e. for someone other than Oswald to have filled out the coupon rifle AND for Klein's not to have processed the order despite producing paperwork to that effect AND to have done so without being paid and falsely entering that payment had been made) is x
3 or 1/1000.
Then you have a rifle photographed in Oswald's hands within a week of when the rifle would most likely have arrived in Oswald's post box. Then that rifle shows up in the very building that Oswald worked in and has prints that are not inconsistent with Oswald's prints and Oswald is seen carrying a long package to work that morning etc. The probability becomes exponentially lower. Even if you put a probability of each piece being false at .5 the probability that ALL of this evidence being false becomes extremely small as the evidence mounts. That is the problem with your position.