Thanks Tim , Dave and dinger.
The replacement door weather strip i fitted is an oval section without air breather holes so maybe the strip i have is an updated version of the vented tubular type. I will try dingers idea too with the masking tape removal. Putty in the intersecting corners seems like a likely spot as well.
You were spot on with your comment Tim about Mustangs being like T models.I have managed to buy every nut and bolt from Must. Country, Cal. If you had that documentation now you would be King Tim and most likely not sell it overseas. You would have books published. The Mustang i have may have passed by you in the factory at Dearborn in June of "67 (marti report) ??????
The local auto Bearing Factory here where i put in 9yrs ,shared product info with the Cleveland Graphite Bronze Co.back in the 70's to make their range of cams, rods, mains etc.
Cheers from downunda.