Another great article is from Sherman Bell, "Finding Out for Myself" in the Double Gun Journal, Volume 17 Issue 3, Autumn 2006. He shot Remington proof loads 18,000 psi and never blew one up.
The most important thing about any barrels, whether fluid steel or Damascus, is what they have been subject to, and in looking at these older guns that have "mirror" bores should bring up a red flag as most likely they were honed. Many of these older guns were neglected and not cleaned, plus the corrosive primer powder left in the bores along with any type of moisture started the pitting action.
Buying one of these Damascus guns or looking to buy one, the first thing would be to have the barrels wall thickness checked, the most critical areas would be from the breech to about 20". By this point the pressure has dropped to less than 500 psi.(initially around 8,000 psi).
The main thing that has caused most of these bursts or bulges is from obstructions in the barrel. The one good thing about doubles, it is easy to see after you shoot one if it is clear.
I hope this helps you in lessoning your fears about Damascus. Also as stated, using the right loads from either RST or other manufactures that make low pressure, low velocity loads or reloading your own.