Greetings,
The Bachmann C-19 actually was made for several different locomotives each has different domes, tenders and such to try and be closer to an actual locomotives, One model has one fluted dome and one round dome, another version has two rounded domes and a third has two fluted domes. Throw in the fact that some have a short tender and others have a long tender. The two painted but unlettered are probably more of a generic model than the others. Most of the research was done in conjunction with Blackstone Models when they came out with their C-19 so I think that they are fairly accurate. In fact the two company's had the very same models in both scale in both the C-19 and K-27. I went and checked the Bachmann web site and they list two versions of #345 and one version of #346 along with RGS #40 and then the two versions of painted but unlettered so you may have to change a few things to get an exact model of the 342.
Andre