This is the Beirette camera that arrived faulty, I thought it would be less hassle to do something with it than send it back to the seller ( he didn't believe it was faulty and just gave me a partial refund...). Anyway, I bought another Beirette and with the body of the faulty one I built the "Pinrette".
I basically took the lens and shutter out and placed a black piece of cardborad where the lens used to be, with the pinhole of course. I used the pinhole camera design site http://www.mrpinhole.com/calcpinh.php in order to get the focal lengh and angle of view desired, the rest is intuition.
I spent a roll of Kodak 125 Plus X trying different exposures and I'm happy with the first results, these ones were about 4 seconds exposure. The pictures are boring as they were taken from my window but I quite like the wide angle and the soft focus.