Grand Funk / American Band is also not fake. Like most of the Capitol Q8's, it's underwhelming. I would also imagine the lack of usable instrument tracks plays a big part. I mean, what can you do with drums, bass, an organ and a guitar? If you listen, the fronts are very dry, the drums are very prominent as well as vocals and organ.
The rears feature (smothered in echo) the vocals, drums but the organ is nowhere near as prominent but the rhythm guitar is very prominent. Lead guitar appears in the front channels with its' echo in the rears. There may also be some vocal splitting front to rear, but it's more a matter of which overdub went where.
If the first song leaves you wondering, the second song on the tape "Stop Lookin' Back", has the drums mixed in more of a "super-stereo" fashion, using all the channels. Organ is very much in the rear but the guitar is front center.
It's not a four-corner, Columbia mix, but it expands the stereo versions a fair bit. It's still quite underwhelming, but maybe that could also be due to some track bleed-through as well. Maybe I was over critical in previous posts, but perhaps a modern attempt at this mix could breathe some new life into it?
(I also believe it to have a swapped channel due to the fact that the indian drums at the end of "Loneliest Rider" pan around in an X (FL, FR, BL, BR) rather than a nice circle around the room.