Thanks for all of the replies - always appreciated. And J_Speegle, thanks for looking for photos. I've been looking for five years for another example of my particular configuration, to no avail.
As mentioned earlier in the thread, I don't have any additional photos of the engine bay from 2017, which is when I inherited the car (I wasn't planning on keeping and restoring the car at that time -- silly me.) Picture below is of the engine bay as of today, but that isn't relevant for this conversation because I have taken out the Thermactor system so I added the adjustable pulley to the dogleg bracket so I could use the AC when it was ready (but as you can see, the AC compressor has no belt on it, as that is not yet ready either.)
And yes, I know there are many parts in my current engine bay that are not concours, including the radiator cap, AC compressor (wrong color), oil cap (wrong color), horn wiring (aftermarket relays), export brace (wrong style), distributor cap (wrong color), compressor hoses (attached backwards), etc. I'm sure there are others you can spot right away. I hope to address all of it eventually, but I have to walk before I can run.
Regardless, what I can say with 100% certainty is that when I got the car in 2017, the original AC compressor and Thermactor system were installed with the same belt running both and the AC compressor lateral bracket was the dog leg variety without a pulley on it. There was also a fixed idler pulley below the compressor, which is just out of sight in this current photo.
Bob, I have the Mannel book -- what pages are you looking at to confirm that the adjustable bracket wasn't used - are you looking at p. 8-54? As mentioned previously, my car was built on 3/1/68 so it was literally on the official switchover day. Based on what I know about my uncle, there is no way he would have switched out a newer stamped steel bracket (with top and side connections to the compressor) for an older dogleg bracket just for the hell of it. I wonder if the SJ line workers that day wanted to first deplete their inventory of the older bracket - did stuff like that occur?