Thanks for the thoughts. The car is a Norwood build. I have the engine out on a stand and did the best I could with pictures. I used lacquer thinner and a brass brush to clean the pad by the oil filter to get a good look. Still no sign of a partial VIN in either location under strong light. See attached pictures. Based on the VIN the car was built in the third week of March 69 assuming a reasonably consistent production rate. As the picture show the engine build date was 02/28. Some sources suggest that is a short turnaround. My son had an interesting thought. What would happen if the engine destined for my car was found to be defective on the assembly line? I don't know when the VIN would have gotten stamped, but if a replacement was pulled from inventory and substituted, it could have no VIN and be built a little later than the original. According to the literature I have, if it were a post-delivery dealer replacement, it would have a CE stamped on the pad by the right head. It doesn't. And, of course, if it had come from another car, it would have that car's VIN on it. Again, it doesn't. Still a mystery. Thanks.