Body/Shell Numbering
Trimix, The shell or body is NOT a reproduction, as you may think. You have to understand how Lionel used various numbers, with MOLDS and TRIMMED bodies. Not all bodies or shells, for all the different locos produced, had numbers cast into the MOLD, but a vast majority did have them. In your case, the 2350; 2351; 2352; & 2358 locos all shared the same body/shell. The number that was part of the MOLD was in fact 2350-5, for all four locomotives. The confusion comes in, when you look at a service manual, that shows different numbers, other than 2350-5. Those numbers actually represent how the 2350-5 shell was TRIMMED.
The 2350-5 body TRIMMED as New Haven carried a number of 2350-2, per the service manual.
The 2350-5 body TRIMMED as Milwaukee is 2351-2
The 2350-5 body TRIMMED as Pennsylvania is 2352-2
The 2350-5 body TRIMMED as Great Northern is 2358-2.
Another example of body mold number, carried through on a different loco, is the MOLD # 671-3. If you looked at the bodies of a Lionel 671; 681; 682; & 2020 loco's, even with the early 1946 version, through until the end of production, ALL HAVE 671-3 as the MOLD number. Each one has a different TRIMMED number in the service manual.
That should explain Lionel's use of numbers with MOLD numbers, versus TRIMMED numbers for different Road Names.