*****Here's the photo after 24 hours rest. The battery is back to just about where I had calculated it would be. I also waited longer and measured it at 34 hours and it was still at 12.26 volts and had obviously reached a steady resting voltage.
*****Using a digital volt meter (DVM) or even an analog one to measure your batteries state of charge can be quite misleading with some rather wide margins of error unless you let it attain an honest resting voltage.
As an update I have since applied many different loads to remove the surface charge. 5 amps, 10 amps 20 amps etc. etc., and all for varying times. The problem is that none of the surface charge removing loads give me an accurate reading that agrees up with a 24 hour rest. I suppose you could do some rather lengthy experiments and find the exact load to remove a surface charge, that works for your bank, at a certain state of charge, but this would be complicated at best. The closest I got was within 8-10%. A 10% variance on a 400 Ah bank is 40 Ah's or nearly a days worth of power for us. Having & interpreting my bank, reading the equivalent a whole day off, can be and would be rather frustrating.
*****Measuring the battery state of charge with a DVM can be misleading if not done correctly or with some real in-depth knowledge of your bank.