RE: BT Bf109E-4
Tubig,
It looks like you are on track with another great build. I tried the iron on technique on my Spit wings. It came out pretty good. I've made progress on my workshop and hope to get back to my Spit soon. This BT plane looks to have much lighter construction that the TF Spit. At 68", it looks like it'll be close to the weight of the 64" Spit. As for ducting and cooling, I've been toying around with the idea of using a small electric ducted fan to aide in airflow. If I find that I need more weight in the nose to balance, I'll test it.
Scott