There are a number of variations on flywheels with belt grooves.
By memory, the VA engine had them on the different side to the CS, Start-O-Matic set engines had them on one side but straight, non-automatic generating set engines had them on the other and so on. If the engine is off the cast base and has no generator with it then it doesn't really matter that much.
Regarding maroon engines, there have been various colour schemes applied by set builders and for specific customers, but the base was always Middle Brunswick Green.
Peter