Tread lightly.
100+ year old Damascus barrel's, even the best of them, are known to let go occasionally.
And when they do, it is Always right under your left hand holding the forearm.
I have known three people over the years with missing fingers & an eye in one case, who just had to try shooting them.
The problem is, it is very difficult or impossible to tell if corrosion has ate away welds in the seams of the wrapped layers of iron / steel over the years.
Perhaps industrial X-ray could spot voids in the metal.
But you sure can't spot it looking down the barrels!
Some say if you strike them, and they 'ring' they are still solid internally.
If they 'thud' they are not safe to shoot.
Myself?
The difference between a ring with one bad defect in it, and thud with enough to make it sound that way is not great enough to risk my only left hand & eyes!
rc
This is worth taking into consideration.
I have only one twist steel barrel shotgun I shoot, and I didn't just take it afield and start blasting.
It is an LC Smith hammer double 10 gauge, and I did quite a lot of testing before use.
The barrels looked great and had a nice ring to them, but that wasn't enough for me. So I took diameter measurements at a dozen points on each barrel, marked with tape so that I could check the same points repeatedly. I then strapped the thing to a lead sled and fired a shell in each tube. Took measurements again, and when everything was the same to within the 0.0005" accuracy of the micrometer, I fired 5 more shells in each tube. Measured again, no change, 10 more shells per tube. This was with 2-7/8" Bismuth shells.
After each tube had fired 16 shells with no measurable signs of fatigue, I decided the gun was safe enough, but transitioned to even lower pressure RST loads. I have since fired dozens of shells, and the old double still seems to be as solid as it was 130 years ago.
Nonetheless, I do not hold this shotgun like I would a modern double, just in case. I wear a leather glove, and I keep my support hand tucked under the forearm, no fingers wrapping the barrel. If it did let go, I'm sure it would still hurt, but the chances of serious, crippling injury to the support hand are far lower. The 9 pound shotgun firing light loads does not require a particularly firm grip toward the front anyway.
There's no reason to not enjoy an old double, but one needs to understand the risks and act accordingly.