Have the C&O H4/H6's changed?

[blwfish]

I know that the original Spectrum 2-6-6-2's were USRA versions, and Bachmann offers them as such. In C&O paint, they are H-5's. I am pretty sure that the next versions offered were H-4's, which to my eye were the H-5 (USRA) boilers with modified front cylinders, with slide valves instead of the USRA's piston valves.

I now see that several of the vendors have older H4 stock and considerably lower prices than ones labelled "new" - but I have no idea what the change is, if any.  Are the current H4 offerings using different tooling?

[digitalgriffin]

10:1 one has sound, and the other doesn't.  That's about $90 in price difference.

For all intents purposes the H4 & H5 are close the same length with a similar boiler.  The H-6 was similar to the H-5 except used the 12VC tender.  So it's an easy mod if you want H-4, H-5, and H-6 in your fleet

Too bad no one made simple simons (H-7).  Then I could have gone from H-4->H-8 on my layout

I still think this would be a good choice for Bachmann as the used H-7's were sold to the UP.  And how many rabid UP modelers are there out there?