Looks like a spaghetti factory. Pure speculation is that the panel was set up for custom AHU shutdown, elevator control, or updated monitoring. Since there are wires next to bottom row PC slots 6,7, and 8 some modules were in those slots at some time. I can’t make out the solder pad numbers in the picture. If you could list some of the pad numbers with wires attached I can figure out what the use is on the cards. Start at the control module slot and a few zone module slots I should be able to help.