Old-Guy wrote:
I can't work out the difference between 453PC0210 (N45332) and 453PC0211 (N45332A), and "I know nuuthing" about Hydractive or Activa systems.

Good work Guy
453PC0210 is an Amtex (pattern) Non-Hydractive front for most applications.
453PC0211 is the same but genuine Citroen...
That's according to the GSF website. Funny the genuine one is 50p cheaper
The Activa ones listed are correct. Note that they don't stock the complete Activa set. No matter as everywhere you can get away with ordinary hydractive spheres
except the Activa accumulator. That one is the same style as an anti-sink sphere but blown up to 62 bars. In emergency an anti-sink will do.
Pleiades will adjust one for this duty.