I've never seen a "new manufacture" barrel for these.
There have been some on eBay/GB in the $150 range in the past but it's a waiting game for one to pop up.
There's a couple different finishes, e.g. early high-polish vs. rougher finish at the end of production if that's important to you.
I vaguely remember someone mentioning relining them.
Another thing to check is cracking where the front "leg", or pedestal, joins up with the barrel.