I'm not the most savvy when it comes to that era in Sunn's history, however...
I would think that the 108G and 1016G designations would indicate 8 and 16 ohm impedance versions of the same driver respectively, that would be in my experience a very "Hartzell Sunn" way of naming the drivers and it just makes sense. Labelling anomalies such as both drivers being labelled "8 Ohms" are regretfully also very common in the Hartzell era, as has been documented here in the past.
The same part number is pretty much a dead giveaway and "seals the deal" by my reckoning.
As I say I'm not claiming to be a "Hartzell Sunn" guru, and the above is purely speculation on my part, but I'd wager it's pretty close to the way it is/was.
As far as using them for guitar; who cares what they were originally designed for? Most speakers in those days and before weren't really specific to the actual applications, they were usually designated by frequency efficiency; e.g. "woofer", "midrange", "tweeter", etc.
Actually I would be surprised if Hartzell DIDN'T use that same driver in a variety of applications, that's how most manufacturers did it back then.
Hook one up to a guitar rig and see what happens. If it sounds good, I'd call it a guitar speaker.
Here's another point; does anyone feel that we really need two threads about this? Both cover almost identical ground, it's confusing to follow, and I can't find a way to combine them, at least so far.
So... Pick one fartheststar, and I'll dump the other one.
To recap; one 108G/1016G thread is plenty, both threads say the same thing, it's confusing and destined to become even more so as posts get added to both.
Let me know!