The hobo camera - $6 DIY 4x5 point and shoot prototype

Since the time I started shooting 4x5 and realized that there's a huge difference in size between my 4x5 pinhole and a Speed Graphic I wanted to get something compact to carry around. Converted poaroids are not an option because of the price tag, custom making one would require some tools and skills and converting a pinhole would require another pinhole which I wasn't ready to invest into. So after a few weeks of thinking and looking for a decent material that I can work with at home I got a $6 sheet of foam board. After an hour with an exacto knife, school glue and vinyl tape I made this.
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I wish I could cut the foamboard more straight, I tried different methods but was never able to get a straight line. So I had to work with what I had.
It can focus to different distances by moving the inner box forward, tacks mark the infinity. Has interchangeable lens boards, I just made one more for my 90mm Angulon.

Here's a test photo. No light leaks but there is quite a bit of focal plane tilt - probably because I couldn't make the film plane parallel to focus plane. But it works and fits well to a dirty look from the film expired in 1969.
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Now I know what to improve and how to make a simpler and more compact version and hopefully I won't have to do it for too long until the Wanderlust comes across :)