after stripping the parts to salvage I think the barrel is ok but just the barrel I was able to unscrew it from where it screws into the piece that has the lugs that piece is cracked and will not unscrew from the from what is left of the upper even with a vice and barrel nut tool. All the barrels I can find seem to have this end lug attached,
You generally can NOT replace a barrel extension as no two barrel extensions time up to the same spot on the barrel.
Also, I would worry about other damage on the barrel.
Just wait for the current parts shortage to clear, them get a new barrel.