Bryan-
Your doors are beautiful! Parts of my house too is over 100 years old, but had been built with doors of whatever they could find...cheap. I have been replacing doors with solid wood ones from an architectural salvage and some newly built ones to match....including installing the mortise style lockset/knobs/backplates.

Since your doors already have a lockset installed, the mortise has already been "hogged out" in your doors. The pocket lockset is easier than any modern lockset to swap out in my opinion. Most are pretty standard sized and only require the removal of the set screw that holds the door knobs on and two wood screws in the face of the cartridge. Buy new, used from ebay, or my favorite: architectural salvage stores. I have some in my home now that are dark oiled bronze color and some the antique brass color like yours. The lock manufacturers back in the day at least had the foresight to standardize the size of most the door knob shafts so they are easily interchangeable.

I found a pattern of door knobs and backplates that I liked dated 1910 at an architectural salvage antique store. After buying out their stock of 3, I kept watching Ebay and bought others to match. Some had the same coloring as yours...some had old paint on them...some were corroded...some were somewhere in between...no two looked the same finish-wise. I cleaned them myself and spray painted them oiled bronze by Rustoleum (from the big hardware stores). They have other metallic finishes to choose from if you prefer other looks. (I don't recommend painting the lockset cartridge with all the moving parts that could bind if paint got in it)

Swapped out the hinges with an oiled bronze colored hinge to match....making sure to match the size and shape of the current hinge. The door knobs, back plates, and mortises now blend perfectly with my doors and the age of the house.
The point is it was Easy Peasey, cost much less, and I got the look I wanted.
Best of luck!