I ask for help, friends! I live in Russia and at us isn't present KF4 only 2 KF2 and KF7, and it to Russia to deliver very expensive, but I was lucky to buy a fuselage in Portugal, wings and a control system in America, but there was a problem - a fuselage probably from KF 3 or early KF4, and a control system from KF4. You couldn't prompt length of these pipes in the photo?
Forgive that I badly speak on English-I only started studying this language!