Factory drawings of Castoldi's aircraft are difficult to find. I myself I can recon to having seen only those for C.300, C.301, C.206 and C.207. If a "factory drawing" could be the one published in the official maintenance manual, then just look at one C.201 manual, there are a lot of them in PDF form on the net. Part of the problem was Castoldi himself, that in late war and early post-war scribbled on a lot of drawings things like "non conforme" and "falso", for reasons unknown. The drawings so scribbled were consequently destroyed. The best M.76 drawing surviving was made by Castoldi post-war for modelers....