I was able to get my hands on a nice W. Butcher backsaw. It is 12 tpi, filled crosscut and about 12 inches long. Original handle, but missing one split nut. The plate is in good shape, no rust at all. Teeths are not broken but probably need to be jointed and then of course sharpened and set.
Butcher is well known for their chisels but they also made adzes, saws, knives and a number of other tools (they manufactured the famous “bowie” knife that became very popular in america).
The mark on the saw is clearly visible on the brass back.
The handle is the classic dolphin pattern:
I cleaned it lightly using Watco rejuvenating oil. I did not want to sand away the nice patina. Interestingly enough, if you zoom in , you will see that two of the split nut holes had the characteristic square mortise in it but the third one did not. It also looks like from the wear pattern that there might have been a medallion in that spot which would explain the absence of mortise:
I have the two original split nuts but not the medalion. I Will probably replace all of that with new ones.
Next I will clean the brass back a bit and joint, set and sharpen it. I am still debating whether or not I want to make it a rip saw or retain it as a crosscut.