[rotorwrench]

It's been so long since I overhauled one of mine that I can't remember where I purchased the gaskets. All of my favorite Mercury parts sources are gone now. Southside Obsolete may have the sector cap gasket. I used to get stuff like that from Stacy Brown but he's gone too. Mine is in the car for the one at my location. The other is stored in KS.

I also have multiple thicknesses of sheet gasket material so I may have made one that approximated the original. The only gasket that is Mercury specific is that one. The shim gaskets for the steering shaft are a B prefix. I may have even found an NOS one on flea-pay but my memory is clouded by all the helicopter components I overhauled since. Getting older doesn't help my memory either.

PS: I may have tried a 7RC-3581 or a 7RT-3581 gasket as well. They are very similar since the 53-55 C & D used an 8M-3580-B cap but older F1 types are also similar.