Actually Birdhunter56 ( Bob ) on the forum did it for me. He can give you the really technical stuff.
The basics are that the ruined barrels of the Red Label were cut off at the mono-block. The mono-block was then reamed out. A new set of barrels was set in place. Exstractors were modified, chambering and headspacing was done.
The barrel contours with the 45/70 are such that the existing forend and hanger could be reused. The diminsions of the stock fit me perfectly as it was so all that was left alone. These things saved time and $ on the project.
He then did the hard thing, regulated it. Got both barrels, as can be seen by the targets, to hit to same POI at about 50 yards. At 100, if I do my part, I think it will drop the two barrels into 2 inches or less. That is more than fine for what it's to be used for.
From what I was able to learn, from asking questions all over the place and reading everything I could get ahold of, the really hard part is regulation. And as a hunter all the estehitics in the world mean nothing if when that hog shows in the palmettos I can't be sure of hitting him.
It was a real learning experence.
Love the rifle.
If I can justify the $ I'm going to have another made in a year or two........just got to figure out what.