Be careful with the comparison between the original 300-series Pullman BTC-1 and the Comet I, as NJT's version was for low-level platforms only, so the vestibule doors and cab front windows were lowered. I'd say the MBTA's cars were more of a cross between Comet I and II, since they did have the window center posts that were a spotting feature of the Comet I while being more like the Comet II in their actual configuration. Of course they're totally different now, having been rebuilt by Amerail to new specs as the BTC-1C class.
There were originally CTC-1 cab cars in the 1300 series, but the surviving ones were rebuilt to BTC-1C along with the BTC-1 coaches. Currently the only cab cars of this car type are the CTC-1B class in the 1600 series, and some of these have already been downgraded to coaches since they're no longer needed as cabs.
Finally, don't make the mistake of including the 500- or 1500-series cars in your list. These are BTC/CTC-3 cars built by Messerschmitt-Bolkow-Blohm (MBB) and although they're dimensionally similar to the BTC/CTC-1 class, they are really a very different breed in many ways.
As noted above, check the NETransit site for more detailed information.