These drawings were made by Niels, Marcel's brother. Niels is a wizard with computers and a big fan of cammy Nortons. When he got one of his uncle's (Ko Konijn) Nortons he took it apart, measured all the components and entered the dimensions and position of each part into his computer. No clue how it works but the results are amazing! It allows him to look 'into' the engine from any angle.
Surprisingly, these are the low quality prints. Niels is working on a book that will contain many more pics of his Manx, in much higher resolution, in addition to photo's and technical data sheets. It may take 'till the end of this year before the book is available though.