If you can't find an original then you need to choose which detail (s) your willing to give up or what option is closer to looking correct
1- You can go the Motorcraft route - It may have the Motorcraft stamped on the face which you don't want and may not have the Stant logo on the rivet
2- You can go with the Stant cap which should not have the Motorcraft stamping or the Autolite
but may have the Stant logo (the big S)
Sorry don't have either of these two here in front of me for a picture - just the process I would consider. I would opt for the Stant one for my car given only these two choices