TW, I can help with a few things:
The marking WRACO is Winchester Repeating Arms CO., ammunition.
Measure the barrel by (unloading it
) the gun and dropping a pencil down the barrel, then measure how much was inside the barrel.
The # 883 should be 8,83 and is the measruement of the lands, of the rifling, it might be 8,84, 8,82, etc., but is close to that size.
The scripted symbol is probably the suffix of the gun, but if you could get a good picture of it? (I find this a very hard place to take a picture and my digital camera fails me on doing this).