Got around to replacing the valve cover gasket on the Miata tonight. I used a Fel Pro gasket that I purchased locally. It looked identical in every way to the OEM one that came off. I used Permatex High-Temp Red silicone rtv on the corners of the camshaft caps, and I'll let it cure overnight before I drive it per the instructions. I bought the car about 2 weeks ago, and it was obvious to me that the car was well taken care of. After seeing the valvetrain with just shy of 123k miles and an unknown (to me) OCI history, I'd say my assumptions about it being well cared for are correct. No sludge, just some varnish. I'll be using synthetic exclusively in this motor. The timing belt also looked good and had good tension on it. This is a non-interference motor, so I'm not all that worried any how. Pictures were taken with my Droid RAZR Maxx HD.