Came across this gun on an auction site. Makes me wonder if the gun is overall lighter and what the wall thickness would measure.
Might take a bit to keep the exterior cleaned up.

https://bid.wardsauctions.com/Non-R...e-break-w-bbl-length-26-Blued_i40069036#

What is the point to the exterior design of the chambers? Never seen SXS barrels constructed like that before. Wall hanger?

It's a H. Pieper tradename gun.
Researcher found them listed in the September 1914, Marshall-Wells Company, Ltd. catalog. Marshall-Wells Hdw. Co. started in Duluth, but the Ltd. was in Winnipeg

Here's a J. Manton & Co. variant