The outer skin sheet metal of the doors and fenders of the cladded model trucks is specially shaped to accommodate the shape of the cladding.
There are pictures on the forum where the truck owner has the cladding removed for some type of project or body work.
While a Silverado door may or may not attach to your truck at the door hinges and close (I have never seen anyone actually try that, however) the cladding IS NOT going to mount to the outer skin of the Silverado door.
On a side note, I recently had to find replacement body parts for a 1993 Ford Explorer that I own that was in an accident.
I can tell you from that experience that practically any body panel or door you could possibly need can be found, if you take the time to look.
I bet, with my recent pass experience, that you could most likely even find a replacement door of the same color of your truck and not even have to worry about paint.
We found fenders and body panels of the exact color of my Explorer.
And that is a truck from 1993.
It took some time and effort, but those parts are out there.
I even found a ton of body parts for my 2004 EXT, not that I needed any, but they were out there.
So I would stop trying to make something that won't fit work and give it a go at finding some parts that will work.
Good luck with your project!