Let's start simple with axles and beams (http://brickset.com/parts/design-6524). If you have a flat bed scanner, a scan of the parts would be the best. Otherwise, a photo seen from top.
For the axles, I need accurate measurement of axle diameter and length, a photo of the tip of axle would help too, as well as a scan or photo of the center of a gear where axle fit.
For the beams, measurement of thickness/width/length, + scan or photo...
For the axles, I need accurate measurement of axle diameter and length, a photo of the tip of axle would help too, as well as a scan or photo of the center of a gear where axle fit.
For the beams, measurement of thickness/width/length, + scan or photo...