V1 model format. Found rarely in Empire Earth 1, but not the native format of any released game.
V2 model format. Primarily found in Empire Earth 1.
V5 model format. Primarily found in Empires: Dawn of the Modern World.
The header, contains the magic number and revision. The current revision is 2.
The expected magic number for all CEM models. If this does not match, then this file is almost certainly not a CEM file. FCC version of "SSMF"