My Australian built Jayco class C has a small generator compartment just big enough for a Honda 2kva or similar, it has an inbuilt sliding tray that the genny sits on. To use it I slide the genny tray out and plug a short lead into my mains input and it works great (with the tray slide out of course). Just what you were thinking of doing.
Just make sure that you ventilate the compartment so that any fumes can disperse when the door is closed.
To secure the genny when traveling I have it tied to the slide out tray with a strap.
