I think it's more likely a combination of all the worn-out parts.
On one hand, you have the flap that opens the steering edge. This flap is almost certainly subject to wear along its edge, even if the design attempts to mitigate this.
'In this case, deposits will certainly form between the distributor piston and the sleeve, as well as inside the distributor housing. Contaminants have a particularly strong effect here.'
Next, the pressure relief valves.
On the low-pressure side, the injection nozzle and the feed pump are most affected. Of course, the eccentric could also fail.
Personally, I believe wear is more likely to occur in the high-pressure components, specifically the distributor piston and the control sleeve.
Starting on the 29th, I can start digging around again

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CU Gremlin.