Sam-
The history is a bit screwy, but it goes like this.
1) The D&RGW (1992) and Erie Lackawanna (1993) were produced by Samhongsa/MTH for Lionel. They featured bodies with nice separately-applied detail.
2) The Santa Fe and New York Central models were produced in late 1997/early 1998 in Michigan. To make them, a large amount of $$$ were spent to remove most of the separately-applied detail from the Samhongsa tooling and cast everything into the body. (A shame, but I guess that was the thinking at the time.) Same thing with the B units which came a year later for each.
3) The black Erie A units were catalogued in 1998, but I don't think they were produced until early 2000 or so. (I remember being in the plant at the time). It was basically the same as the Santa Fe and NYC except ElectroCouplers were included. The B unit came along in 2000.
4) The Pennsy's were shown in the 1999 catalog, and as you mentioned, were scheduled to have the Odyssey motors. Once that program was canceled in 2000, the units were changed to include two standard can motors but with the Odyssey system for speed control. If I remember correctly, the Pennsy's (including the powered B unit) were the only diesel locomotives produced in the US that have the Odyssey system.
5) A set of Delaware & Hudson Alco PA's were scheduled for production in the US for 2001, but due to slow sales of the Pennsy and the pending move to China, they were canceled and never announced.
6) Prior to bringing out the next run of Alco PA's, I had some quotes generated to restore all the separately-applied detail to the cab. The short version is that it wasn't worthwhile to put more dollars into the old tooling, therefore everything from here on used Alco PA tooling that was new from the ground up.
7) The first batch of all-new Lionel Alco's were the Santa Fe, Delaware & Hudson, Union Pacific and Freedom Train, produced in China in 2003. These last two only came in sets. And if you're curious about the "sleeper" of the bunch, check-out the Freedom Train -- it's neat.
Regards,
TRW