With pleasure.
From the Kleins ad, Oswald ordered C20-T750 and Oswald received C20-T750


And in addition, the rifle in evidence found on the 6th floor shares the exact same serial number that Kleins sent.

Now agree with me!

JohnM
No, because there are too many leaps of faith and not enough credible evidence to support your claims.
From the Kleins ad, Oswald ordered C20-T750 and Oswald received C20-T750First leap of faith! Show me proof that Oswald received anything. I don't believe there is, or ever was, a mail order business that ships merchandise without any confirmation of either shipping or receipt.
Secondly, details matter, even when you like to ignore them. The order was for C20-T750 from Department 358 (the February 1963 issue of the American Rifleman) which is not the same rifle they offered as C20-T750 in the April issue. To just assume that Kleins' would simply send out another rifle than was ordered is another leap of faith. The WC did not even bother to ask Waldman about the sending out of a rifle that was different from the one ordered. One can only wonder why.....
And in addition, the rifle in evidence found on the 6th floor shares the exact same serial number that Kleins sent.Wrong. The rifle found at the TSBD has the same serial number that was hand written on Waldman 7. There is no way to verify when the document we know as Waldman 7 was actually made and by who and it most certainly isn't proof of any rifle being sent, nothwithstanding Waldman's explanation of the meaning of the also hand written letters "PP" on the same document.
So, sorry, just too many leaps of faith and not enough authenticated evidence to justify the conclusions you are jumping to. It is beyond belief that something this basic needs to be explained to you.
Btw, there is something I don't really understand. That Kleins' made copies of order coupons on microfilm I can understand. That's probably a better way to keep track of all incoming orders than saving all those coupons. However, as Waldman explained, document 7 is an internal order form which is generated for each order. Why in the world would they copy that on microfilm as well and not keep the original?