Trimmed out the front and back inner skins and did a test fitting. Amazingly, everything seems to be lining up! I need to put some reinforcements on the sides under the shoulders to give the side seams something to glue onto. I am thinking that four 3mm sheets glued together would provide more than enough purchase. I also noticed that even though I am not going to have the arm boxes, I do need some support behind there. I must have missed that step on Dave's plans!
I anticipate that the outer skins will be much more time consuming to trim, but I am going to go slowly because I do not want to do this twice!