David,
Those anvils and many of the tools had been developed to produce blade weapons and armor. Take a good look at what they are doing. Wrapping metal around a mandrel. This was the primary barrel making method for centuries. It remained the major production method for damascus barrels to the very end.
Here (circa 1924) the anvil has been specialized even further. It has grooves to hold the barrel as it is formed. This specialization had occurred much earlier.
Here is a modern (circa 1970) recreation of making barrels (circa 1750) by forge welding fluid metal around a mandrel. Notice the hammer, very similar to the one shown above.
What Ed notes is important. They had begun to "play" with choke boring. Something that most people think was a later development.
Pete
