I don't think I have a pic showing that specifically. However, there are some pics that will help at Matchlessaero's page:

http://www.geocities.com/matchlessaero/halfwit.html

If you look down towards the bottom you'll see a red HW with the fuel tank mounted on the side behind the engine. Now just figure that you can place the battery on the other side of the fuse basically across from the tank.

As far as covering, go ahead and cover everything. I did the same thing, then cut a square out on the bottom of the wing for mounting the servos and radio gear after the plane was built. Then I just patched the holes with a piece of covering.

Duke