Eric:

Any place fuel is likely to wet should be fuelproofed. With the tank shoved up inside the nose, fuelproofing the tank area is difficult. My somewhat effective method is using a spraycan of fuel proof paint and fogging the inside. Doesn't get everything, but it's better than nothing. Theoretically, the entire inside of the plane should be treated, but worst case is usually a burst tank, when that happens the engine quits and you land. The fuel seldom gets further than the radio area anyway, often doesn't get that far. So, if you seal the tank area and the floor of the radio box, maybe a bit up the sides of the radio area, you have all you need. You can overdo it - the paint or epoxy adds weight.

Hope this helps.

Bill.