Minifigs Plains War Figures (The IW Range)

One of the readers of this blog shared some images of a lesser known Minifigs 25mm range that covers the US Plains Wars (Indian Wars) between the US army and the Native American tribes.  The range started off as part of the early S Range, then morphed into the current more 'chubby' style range. There is scant information available (or if there is it is hard to find) about these figures and there are some gaps in our knowledge.

Listed below are pictures of examples of what is known to exist from both the old and current ranges:

1. The four examples of 25mm mounted Minifigs S range U.S. cavalry for the 'Indian Wars' series.

2. A comparison between the S Range Indian Wars on the right and the S Range ACW US cavalry mounted figures on the left:

3. The complete 25mm Minifigs IW Native American range:

4. The complete IW S Range Native American 25mm Minifigs:

5. Four infantry and four gunners:

6. An infantryman and four gunners produced by Minifigs, that have the same IW codes on the bases, but are clearly different sculpts (perhaps an interim range?).

7. Two U.S> dismounted cavalrymen; 25mm Minifigs castings from the later (current) 25mm range.

8. Examples of current range U.S. cavalry (top) and Native American horses.

Of not, the current range figures in photos 5 and 6 are different castings but bear the same codes. Were there two ranges produced by Minifigs?

I would be interested to hear from anyone who has more knowledge about these figures and can explain the odd arrangement of different figures with the same codes.  Does anyone have a collection of these figures, both current and S range?

I note that on the Miniature Figurines website that the IW range is currently out of production, but there is a list of figures, as illustrated above.