Unsolved Edited Pigeon

So here is my model. remodeld the pigeon to be long. I've been experimenting with the JBeam.

Since I have extended the frame, body, axel, and exhaust pipe I'm going to have to change the jbeam. I have messed around with it a lot. I have also used the BNEditor.

For example to maybe do it - have the extended frame in blender and than use the jbeam exporter plugin?

I've done a lot of research in past few months but maybe not enough. haven't found anything on the wiki that fits what I'm doing.

 

now when you say duplicate structure of the cabin only the cabin? also here is the file.