Can anyone identify this component? Looks like an op-amp
It looks to me that they are using a second LM723 as a comparator. The output in this chip is more like a voltage follower rather than the open-collector output favoured in typical comparators.

Figure 1. LM723 pinout. Original pin numbering is for the metal can variant. The yellow circled numbers are for the 14-pin DIL and match your schematic.