Out of interest how did the transition date get determined? My copy of UPC 0 B1 is hard to read but it looks like view B (& possibly C?) were added in August 3rd '69 Revision 10. However, item 6, the vehicle certificate, would appear to have been already on the drawing prior to Revision 9. Is the date as per one of those earlier revisions which is not recorded on my copy? Thanks!