Back when I was beating on guns for a living, and principally building custom 1911 pistols, I used to offer what I called a "PPC."
The "Politically Correct Carbine" was a good option after CA made it challenging to keep our ARs FNCs Galils, etc. I would do them on either Marlins or Winchesters, and the work was pretty simple.
*Cut barrel and shorten mag tube for minimum legal OAL.
*Mount Ashley ghost ring sights, often with a custom milled heavy duty ramped front sight soldered to the barrel.
*Open the lever just a bit for glove use.
*Modify the stock to stow five or six reserve rounds in the butt.
*Mount a thin rifle pad and round the heel of the butt for quick mounting.
*Refinish if desired, usually parkerizing.
Personally, I think custom barrels and truing would be folly. It's a short range rifle and cartridge, but it does work very well for the intended role.
I have photos, but nothing digital. You can easily imagine the resulting package. Good luck with your project!
Cheers... Jim