Notice today on my 69 that there is a slight difference between the front fenders. The drivers side is a replacement, but at the front you can see the top mounting lip is rounded on the drivers fender and a straight corner on the passenger fender. The passenger fender is original, but I’m wondering if the drivers fender is actually from a 70?
Well, since they went to the larger side markers (all four of them) in '70, no other way to do it! Probably a safety mandate or something. People have interchanged the fenders though, just have to deal with the marker opening, otherwise it will fit and look the same to my knowledge.
The 70 front sidemarkers have DOWB part numbers which are specific to Cougar. There are also DOMB and some others part numbers out there for other model lines. The lenses, I believe, are shared but not the housings nor the backing plate assemblies. I seem to recall that the rears also have DOWB part numbers but just can’t recall off the top of my head.