There are some strong parallels between the Rochester to Kessler transition and the American Luger to Carbo Jet transition. In both cases, there was a company name change and then during the transition period some guns were produced by the new company, to new spefications, but the guns were marked with the name of the old company.
With Rochester/Kessler, Kessler first production guns were made with parts from both Rochester and Kessler manufacture. The guns are clearly marked Rochester but there is no question that it is actually a Kessler, because we have the Kessler owner's instruction manual showing this same model using the same odd combination of parts.
With American Luger/Carbo Jet, Carbo Jet's first production guns were made to the Carbo Jet specification (adding variable power.) The guns are clearly marked American Luger but there is no qeustion that they are actually Carbo Jets because we have the Carbo Jet owner's instruction manuals showing this same variable power model. In this instance however Carbo Jet never made it to full production after the transition period.
There's a lesson to be learned here. It's can be extremely difficult to correctly figure out company production history without complete documentation. In the above instances, just looking at the guns, without knowledge of the associated paperwork, it's easy to come to the wrong conclusion. Sometimes things are not exactly what they say they are. Something marked Rochester can actually be a Kessler. Something can be marked American Luger and yet be a Carbo Jet.