I had a look at the entire album last night in my DAW and in a nutshell, and the bad news is I think the front left and front right channels are swapped but the good news is it doesn't massively impact the integrity of the mix. I'll try to explain.
My normal methodology for checking for incorrect channel assignment is to check some or all of the following:
1. Check for side panned tracks, ie things that are in the front left and rear left, or front right and rear right. If you're hearing the same instrument in only the front left and rear right (or vice versa) then this usually indicates a channel assignment error.
2. Check to see if reverbs from front channels can be heard in the rears, or vice versa. For example if you had a guitar in the front left and there were reverbs in the rear speakers you might expect to hear the reverb more in the surround left speaker. This method isn't definitive but it adds weight to a conclusion.
3. Do "ping pong" effects (ie swirls and moving instruments) move in a natural, logical way?
For this album, #1 is out because there are absolutely no side panned instruments on the whole of the album - most of the album is discrete drums in the rear speakers, but when there are instruments in the rear speakers, like the backing keyboards on Birds Of Fire (track 1) they are entirely pushed to the rears. #2 doesn't work because the reverbs used from front to rear (and vice-versa) are completely mono. For example during the drum solo in the middle of 'One Word' the drum mix across the rears is a stereo mix, but the reverbs from the drums in the two front channels are effectively mono. I'll get to #3 in a moment, but first there are two exceptions to what I've said so far that indicate the front channels are swapped.
The first is track 4, 'Sapphire Bullets Of Pure Love' (which is more a collection of random noises than a song) but the waveforms seem to show a decided channel swap. It's possible this track was even some kind of upmix/unwrap because there's a lot of stuff where audio information in the front speakers looks duplicated in the rear speakers at lower volume. I've put red circles around audio events that I feel are good examples of parts that identical or similar between front and rears, and as you can see when they're identical, it's between pairs of front left/rear right or front right/rear left channels, which would create two diagonal soundfields and probably make smoke come out of the ears of the SQ encoder.
The second exception is the following track, 'Thousand Island Park' which has the acoustic piano in all four speakers. There's no way to really show this visually, but if you listen to the front pair of speakers the piano is in stereo with the higher pitched keys panned toward the right, whereas if you listen to the rear speakers, the piano is in stereo with the higher pitched keys toward the left.
And finally, addressing point #3, ping pong effects. There's only one of these in the whole album, and it's the snare drum roll that starts track 7 'One Word'. On the SACD as-is, it starts in the front right (briefly), moves to the front left, then goes diagonally to the rear right, then to the rear left, then to the front right in a weird sort of 'Z' pattern. If you swap the front left and right channels, the pan starts in the front left speaker and does one and a half slow swirls around the room, ending in the rear right. To me that seems much more logical than a hectic 'Z' pattern.
Also, in thinking about it, I don't think the kind of quadraphonic joystick they were using back then would allow them to do diagonal pans. Correct me if I'm wrong, but lets say you were moving your joystick from front left to rear right - when you had the joystick equidistant between the two points, wouldn't that be in the center of the joystick pad, and thus, wouldn't sound be coming equally out of all four speakers?
(This is the VU meters during the final (loudest) part of the drum roll as it's moving from front left to surround right on the uncorrected SACD. It clearly shows the FL and SR channels as being loud and the FR and SL channels as being quieter) something I don't think is possible other than the result of a channel swap.)
So, in conclusion these are my reasons for thinking the front left and front right channels are swapped on the SACD:
1. If you switch them, the instrument layout (violin - keys - guitar) in the front speakers of the quad mix matches the instrument layout in both the stereo version and the SQ vinyl.
2. Sapphire Bullets of Pure Love and Thousand Island Park both have diagonally panned information between front and rear channels, which is an SQ encoding no-no for the same reason that there's never any center panned information in the rear speakers of SQ mixes.
3. A 1.5 rotations 'drum swirl' at the beginning of One Word seems much more logical than the 'double Z' pattern that the snare takes on the SACD as it is now. In fact I can't think of any Columbia quad mixes that have diagonal pans, where there are piles of examples of swirls, including a bunch on Santana 'Abraxas', the flute solo on Just You 'N' Me From Chicago VI, the bass guitar at the beginning of the O'Jays 'For The Love Of Money', etc. etc.
I agree that the case for this having swapped channels isn't a slam dunk like some of the other ones that myself and others have discovered, but I'm pretty confident that I'm right. To be honest with this album it's not as diastrous as others - I think the only time it would bug me is the 'One Word' drum swirl. By the same token, I hope that if AF re-press this title that they do correct the quad transfer and swap the front left and front right channels.