@Dan Winterland
First of all, it's not true that auto-brake is mandatory according to Airbus SOP. It's still AS RQRD
Regarding the brakes, old system is just a little bit different but not that much that it requires too much brain storming. It has no ABCU and some controls are interconnected little bit differently to HYD system.
Procedue is straight forward as you copied it from your FCOM. Only difference is that you loose NORM BRK and that's why you have to calculate LDG DIST PROC. You have fully functioning ALTN BRK. But with old system pilot needs to restrict brakes pressure manually to max 1000 PSI. On new system ABCU does it for you.
LDG DIST is some 10% more for DRY or GOOD RWY if memory serves me good.
If the RWY is extremely short or contaminated and you want to recalculate your LDG DIST to be sure, it makes sense to do a go-around, but if they declared emergency only because of that, it's ridiculous.