Not sure if it's been posted here or not and I missed it, but yesterday I was on ERR's web site to get the links to the sound samples and noticed that they now have a steam turbine sound set for sale!!! I can now upgrade my beautiful MTH PRR S-2 (30-1149-1, the real nice Protosound semi scale one, not the tiny Bantam one.) to TMCC command. Here is a video of the locomotive, and here is the ERR sound set. Not quite the same, but still better then a turbine chuffing.
Now if they could do one for gas engines like Doodlebugs, and one for little electric trolleys, I'd be set.