I built two of these gyrocopters at the same time. I glued both halves together and then held them together with rubber bands. I buy those little rubber bands that women use to make pony tails. They are sold in the hair care products section of many stores and a lot of them are only a couple bucks. They are so cheap you can cut them off without having to worry about the expense.
I built two V2 missle types and two Me109 fighters and these two Fi 265 all about the same time.
The Me 109 was the primary German fighter in WWII. I have several in my collection and I am building more. Even up to the last few days of the war, the Germans could still muster enough planes on the Easter Front to acheive limited air superiority in certain areas.