I'd do #3. If that Brazilian is nicer than most, that's worth saving, and add to that the fact that it has military pedigree. If #2 is original, with that number it probably saw duty during WWI. To me, that carries value.
If #3 is already refinished, then you won't be hurting it much- might even get away with a chop job and cold blue the muzzle?

I definitely vote for Wiregrassguy's idea.

How short are you going with the barrel?