Strange coincidence.

I also became too curious over the weekend and took the cap off the fuel aneroid (aka boost device) on my engine and had some oil spill out. It felt a little slower (nothing major) at the start but 200km later it's back to feeling normal. I imagine the oil that spilled from mine was blowby from the bottom of the inlet manifold as the pickup line used to run from the lowest point.

The local diesel injector service guys said the screw in the middle of the back of the aneroid is the lower limit. Screwing it in (or replacing it with a longer one) will give you more fuel off boost without affecting the maximum fuel delivery. This makes sense from what I saw inside.