It was rebarrelled at some point, probably when it was rebuilt in 1895, and the barrel would not have the .38 Special dimensions so it would probably not be very accurate with those cartridges. I think the cylinder was probably reamed at a later date.
It had to have been rebarrelled, else how could the barrel have a patent date five years after Kimball left Colt? And since he inspected it, it had to be made before he left in 1890, which means it had to have started out as a Model 1889. Since the Model 1889 had no cylinder notches, the cylinder had to have been replaced and the inside of the gun reworked for cylinder stop notches.
Colt stamped the assembly number on replaced parts when they rebuilt those guns.
As to value, it is an interesting gun, and had it still been as originally made it would have been more valuable. But as I said before, without a good picture of the gun, it is hard to even guess at the value. And without a serial number, it is not going to be easy to sell, antique or not. If the overall finish is no better than the butt, I would say $250 or so.