There should be a few thousand teenagers in basements in Romania who would be willing to dis-assemble the code for them.
“Can you run that report that someone ran for me in 2004?”
“Do you have a report name for it?”
“No, it was 13 years ago!”
wrong.
If the code has not changed since then, and the change was simple enough, the binary produced could be nearly identical to the original.
like if you change a “+” sign in an equation to a “-” and then compile using the exact same build environment, you could get a binary that differed in just a couple of bytes.
I strongly suspect that they have the entire build environment available so they would have have to recreate it and THEN make this simple change, otherwise you’d have to do a complete integration test.
I would not doubt that the computer to build this exists virtually, with all the source code.