Greetings,
I was the owner of an Indus GT in the mid 90’s when I went through my first period of “Oh my God I have a decent paying job and now I can have all that bad ass atari stuff I wanted in the late 90’s…”.. Anyway the Indus I had had the serial # label for the Indus just like all of them do - but also had the CPM chip, and a separate label for that.. To this day, I cannot recall seeing an ebay or craigslist auction that had both labels - which leads me to believe that (perhaps) the cpm chip was an add on thing mostly, or/and coming stock with the drive was a very rare thing.
I doubt there are any numbers to back this up as its kind of an eccentric statistic - but I was curious what others within the collective thought?