If your model has a nosecone, than my tip will be helpful. if not, then too bad! First, don't glue the nosecone on. If you need to do some final balancing adjustement, just add clay to the inside of the nosecone. works great.
The P-38 is arguably the best... Forget that, it is THE BEST fighter of world war two, and is epically AWESOME!
Squishyp38