Went through my pictures and can offer the following. These are just the latest built cars I have - all from July or August 67
Dearborn Cougar and Mustang
NJ
San Jose - Not a great picture but the engine is in the car. Other pictures of the car are in a thread and I have spent a number of hours with the car and no added support there. Just used it since it was the latest built car that was handy
If your shows a 67 I think someone wanted to repair or reduce the chance of cracking, as they often did (like the first picture above) and someone added either the whole shock tower from another car or just the plates. Have seen this done
Did also notice that in your picture there are some additional welds that were not typically done on 68's with the plates - further suggesting IMHO someone has been in there playing around