Can Creek AD5 Rear Shock rebound damping

[adamr]

Hoping someone can help with this. I have this old shock that works just fine - recently serviced. The rebound damping however is basically non-existent. It is controlled by a Jet inside the shock much like the jet in a gas stove. I need the one with the smallest jet diam to maximise the damping. No help/response from cane creek or their local distributor. Anyone have an old one around or some advice other than get a new shock?