I like the Moach 737 Experience because it has a VC, but unfortunately that VC doesn't have any night lighting (I have version 1.2). No floodlight, no backlit gauges, so it's really hard to fly the plane at night, not to mention unrealistic. Does anyone know how to fix this? Should I try copying some of the default 737-400's textures into the Moach texture folders?

There is absolutely nothing you can do to "fix" what was omitted.If the authors did not provide for proper lighting in the VC, you can't "add it" to the .mdl file.These days there is no excuse whatever for not having proper lighting, seeing as how I published a tutorial on the topic nearly three years ago... ;)

The most you could do is add a domelight fx to the inside of your cockpit...Also, copying textures from another aircraft will not help, unless it has the exact same filename and same texture layout, you will either have just extra unused textures, or you will overwrite Moach's and be left with a mess when you view the VC...