In the January 1976 issue of the NMRA Bulletin are drawings for a C&S Standard Frame Trestle listing all wood sizes, an HO scale drawing of the timber bridge at Weir Gulch (creek) and a C&S Pile Bent for standard trestle bridges. All material dimensions are given but I don't know if this data can be posted on the site without the approval of the NMRA; might be worth a look.