I don't know about this set but I have a WR set made in 1864 going to a client that have exactly the same construction and they are indeed a shoe lump.

It is not that modern steels are better or not really that is under discussion. Rather that it is almost impossible to buy barrels that are not modern alloy steels. The discussion is if it is OK to TIG weld such steels to older steels of unknown composition. I am quite certain that in engineering applications other than firearms where the same grades of steel are used it would not be contemplated without extensive pre and post heat treatment. The question is if it is indeed being done in the firearms field and what engineering/metalurgical principles are being applied apart from SWAG.

As I said in a post above, I don't normally deal with shotguns. I was suprised to find that TIG is being applied here. But those doing it are apparently happy with the process. The TIG is at the joint between sleeve and old barrel/monoblock. Apparently no other fastening method is used. It was unclear from my brief conversation this morning if it is also applied at the breech end to seal the liner here. I will know more next week. There is no TIG at the muzzle this is traditionally soft soldered.

Regards