There are quite a variety of "mechanic's mirrors" in all kinds of sizes and shapes. You can likely find them at most decent hardware, auto parts, etc shops.

If you're fortunate enough to have one of the mini (2xAA) maglights®, remember that you can screw the lens cap completely off and stand the light in the cap for a "camp candle." With the cap off, and the bulb stuck in beside the mirror, you should have "360-degree" lighting of about everything inside. (It avoids having to aim the mirror and the light so they line up.)

John