Anyone have any original fenders? Need to see what area of the backside of the fenders Ford sprayed with that black undercoating.
Any pictures?
Any Mustang front fender from a San Jose car will provide the same idea of what they did there around when you car was completed at SJ. Its typically between very little but not has heavy and the back east plant. Remember when reproducing the size, shape and pattern, the pattern from the inner fender panels and the back side of the fender need to match and make sense. On lighter sprayed cars often you will find an "attempt" to spray the area where the splash shields and fenders come together while toward the middle of the bottom side of the fender the rear and forward inner panels applications are joined front and rear patterns. Can be more difficult to show in pictures and describe 3D areas. Also we can't tell you how your specific car was sprayed. A good reason to take and keep pictures unless the car has already been redone over the years.
Guess you missed this guide when you used the search feature. It might provide enough information for you but if not we'll plan on covering more or other details you may have. Looks like pg 14-15 might help
67 San Jose Undercarriage Finishing - A Guide (https://www.docdroid.net/dNrBoiu/article-opensource-67sanjoseunder-19v6-pdf)
May be able to show some examples for the same time period as your car.