Actually, that is not an experimental version.
It is the first wrecker in the HEMTT line, the original M984 . . . while it wasn't the best version they produced it was by far my favorite, as I ran one for 3 years.
It does have a midship main drag line winch, as well as the boom mounted winch line.
You could very easily use the boom for towing, it had braces that had to be installed to do it though.
Not exactly a "user friendly"design with all the braces that had to be manually installed to do any "heavy" lifting with it, those braces also made rotating the boom impossible when they were installed.
I used mine to pull the pack on our M88 on a regular basis.
The more common versions of the HEMTT wrecker that most of us have seen, started life as the M984E1, "E" for experimental.
Once they were finally approved as a final model, they changed designations to M984A1 . . . we had my original M984 in my unit for 2 years before the first M984E1 showed up in our motorpool . . . and yes it was an E1 version, not an A1, based on the data plate on the dash.
Not sure what changed when the A2, and A3 came about . . . but I know the lifting capacity of the A1 wasn't near as great as the original 984 when the braces were installed and the boom being midship made it kind of a pain to use compared to mine.
But as far as towing was concerned the A1 was far superior . . . no more tow bars
Anyway I hope that clears up any minor confusion.
I love these rigs to death and those are some of the best pics I've seen of an original M984 since I got out.
Oh and the M88A1 is in the third pic, off to the left.
Tracked heavy recovery unit based on the M60 tank chassis.