One of the amazing things about the DW revolvers is that, through the 4 different "regimes" which have produced the guns, the parts have remained identical and interchangeable. (Model to model, of course.) Barrels, sights, grips, even internal parts are the same throughout the years.
The only real exceptions were the fixed-barrel guns in the Palmer days (which of course wouldn't take the shroud/barrel assemblies), and the hammers of the current production Norwich guns (they are of a different pattern in the double action strut.)
Getting finishes to match precisely, of course, can be a problem - but then, the same can be said of every other revolver manufacturer over time.