Ralph,
This one is a head scratcher for sure.
With the guage cluster in the cockpit it is subject to flooding especially the ignition switch. It has happened to me twice.
With a sealed hatch over it you need to open it before using the switch and close it after the engine is running and open it again when shutting the engine down or leave it open with the chance of flooding.
With the cluster mounted inside down below it is difficult to monitor the guages when under way and you may not hear the engine alarm when it sounds. Also this means a trip below to start or stop the engine.
I am leaning towards leaving the guages in the cockpit behind a sealed panel of lexan and mounting the switch and kill button on a small bracket just inside the companionway where it can be reached easily. Of course with all new ideas there are new problems such as running the wiring so it doesnt look like a total hack did it.
Good luck with yours, Lee