Hewland Mk8 Sideplates leaking

The side plates on my Mk 8 are weeping/leaking. I've check the bolts and they were tight (didn't actually torque them).

What if anything is used as a gasket/sealer. The Pegasus website states that Hylomar blue should not be used on the sideplates.

Thanks,
Jim

Hewland Mk8 Sideplates leaking