1. Have you calibrated your hydrometer by measuring what it reads in 60F water?
It's not unusual for them to read a few points off. I got a supposedly precision finishing hydrometer that only read up to 1.020 on the scale, and it was 5 points off.
2. Did you add any top up water, and if so, did you stir it really well before taking the gravity sample? If you did top off and the wort was not adequately mixed, you could have taken a sample of diluted wort.
3. I'm puzzled by your description of the sparge. You say you slowly ladled the sparge water into the MLT? If so, were you draining the wort out as you were adding the sparge water? If you were, then you were fly sparging, and this does not work well with a braid.
If you added all the sparge water before starting to drain (batch sparging), I cannot understand the reason for slowly ladling water onto pie pans. If you were fly sparging, I would suggest doing a batch sparge. After the mash, vorlauf and drain all the runnings quickly, then add the sparge water (do this quickly) and then stir really well. Then vorlauf and drain the second runnings quickly. This should give you very much better efficiency than trying to fly sparge in a rectangular cooler with a braid.
-a.
