The lensboards are approx. 14X20 cm in size. Sure, I know what you mean, it sounds like over kill, but it was the method used in making the origional lensboards, so he's just staying true to the style, and I must admit, I like his attitiude! Take another look at the picture of the camera. The problem is, the lensboards slide in a tongue and groove system, allowing for a front shift. If the lensboard warps even 1mm (as he explained it to me), it's going to no longer move in the track properly. And on top of that, a warp would/could also lead to a light leak, again because of the system with which the lensboard is mounted to the camera.
See pic for how the panel has been divided into three sections with the grain running in 2 directions for stability.
The glue, as it was explained to be, is produced by cooking animal bone until it reduces to a sticky glue. It is then allowed to dry, and is then ground into small pellet shaped beads about 1mm in diameter. This is how he buys it from his supplier. He then melts the pellets creating again a liquid form. He showed me pair of maraccas he made using this glue to attach the handles to the gourd. This glue is amazingly strong and dries to a slight caramel color.