Re: Marinetics LPG Control Panel
Agree that looks like a standard panel-mount fuse holder.
For lack of wall space when I needed to add a few more breakers, I replaced my LPG panel (different make, but still just a switch, fuse and light) with a four-breaker panel, fitted a 5A red-toggle breaker and red LED to the bottom position, and labelled that one PROPANE. It does exactly what the old panel did in much less space. The other positions power the VHF and HF radios and one spare.
Basically unless your panel includes a gas detector, it's just a fuse, switch and pilot light. One could replace the metal panel and get all kinds of creative with the switch/light arrangement.
1998 Jeanneau SO45.2