Got the barrel rechambered, took 3½hrs and a couple blisters even wearing gloves, I'll never do another 44mag to 444 Marlin rechamber by hand again, just too much metal to remove.
The chamber did come out good, polished it a little with a piece of 600 wet/dry affixed to a bore mop, looks good, with just a very faint ghost of the original chamber, not near as much as was left in my 357Mag to Max chamber.
To locate and help maintain the position of the forend stud for reattachment, I made a simple fixture using ¼x1 mild steel and a .375" pin from True Value, it worked sweet, once the mounting surface of the stud is prepared, in this case milled flat, I tinned it and the barrel, then clamped it in position with a spring clamp, heated the barrel with a propane torch, when the silver solder melted and the clamp seated the stud, I applied pressure to the end of the fixture towards the pivot to make sure the stud was in the right place, once it was cool I could push the pin out of the pivot and the stud was perfectly positioned, the forend fits perfect.
Last night and this morning I made a fixture to help mark the barrel, it's just a piece of 1" electical conduit split lengthwise with a slot cut in it, to that I soldered a piece .375"x1" 4140 that I milled on once side with a 1" ball end mill, then "adjusted" the edges of the cut so it fit the contour of the fixture, it has a ¼" "window" milled in it to help align the steel stamping tools which are ¼" square, the fixture can be pushed onto the chamber swell and stays in place while doing the marking. My first attempt marking the barrel is much better than any I've done before, but practice makes perfect, making sure the stamp is held at the same angle is much easier than doing it free hand, not perfect, but it's good enough for who it's for!!
Tim