RE: Anyone have a maiden flight like this.
You never know what's going to happen when you design a model from scratch, especially an unusual design. With WW1 planes you can have all sorts of design issues like thin undercambered wings, various amounts of wing stagger, lower wing with narrower chord, various wing incidences, etc. Figuring out the correct CG on your own gets very tricky.
The first flight of my Hannover was just about as bad as this one was. I calculated and recalculated my CG until I was sure I had it in a safe location, but sure enough, on the first flight it was tail heavy and was extremely difficult to control. I was lucky to get it down in one piece! I went back home, added weight in the nose and bit the bullet and reduced the wing incidences from scale. Now it flies beautifully and has many, many flights on it.
You just can't be sure on that first flight with a model of your own design. The number of days to build doesn't matter. If you have the tools, materials, and motivation, you can build a good model in a very short time. Now, detailing it out is another matter![8D]
Jim