With Walter Woods amp history, things are not always neat and tidy. There are lots of variations: models he only made a few of, transition models, amps he updated for customers later. I spoke with Walter at some length about this just the other day. He was always experimenting and changing things over the years.
The early/transition Electracoustic amps are particularly fascinating to me. I have a green light Electracoutic M300 made in January '97. It looks very much like a new Electracoustic except it has a provision for an XLR direct out on the front panel, while some very early Electracoustic amps actually have an XLR direct out. I think most if not all of the MI 200-8 "Sweeper" amps have one or two XLR direct outs. As noted earlier, there are Sweeper-era amps that had an Electracoustic front panel/preamp added at a later time.
Even WW amps that look the same externally can be quite different inside. I sometimes wonder if any two Walter Woods amps are exactly alike.