Here are the fore and aft sections dry fit over the frame.
Add the two sides that will be connected to the aft section at this time
Note: the cutouts for the main wheels. I elected not to install the wells on the frames. Those will be built later due to the possibility that they may not match the wing cutouts later on.
Now cut the fuselage frames as shown. Each half will then be inserted into the fuselage halves and then joined.
Isaac