It turns out that regardless of what rated ampage your alternator is if you have a Bosch BR14-M3 alternator fitted then they all take the same regulator.
Common reasons to replace the regulator are if the brushed are worn down or (like ours) if the diodes begin to breakdown and you either get voltage issues or a current leak causing a flat battery when parked up.
The Bosch part number for the new regulator is F00M144139 which supersedes F00M145248 which is what I had fitted. This regulator is suitable for 90/120/200A units.
Bosch won’t release or send out spec sheets but details can be confirmed with them direct, just speak to their automotive technical department: