<span style="font-size: small;">Devildog,

I don't know if you still need but here is how I layout my SLU in my Panzer 3, I just installed last week. It is a pretty tight fit.
First I removed all the plastic mounts that held the old Heng Long electronics and smoker. I angled the SLU in the back and removed the clear plastic that's on top for some extra space.
For the apple, I laid a piece styrene on top to cover the old switch hole then cut a slot to insert the plug and epoxy it in place. Because the Panzer's cupola can be twisted on and off , I insert a cut down crazy glue container up through the bottom of the </span><span style="font-size: small;"> cupola </span><span style="font-size: small;">where it fits snugly, then twist it back on over the apple for protection. I just have to finish cleaning up the wires a little, but I have already taken it for test drive, and hands nicely. It may become my new favourite battle tank. </span>