Finally dug some tips out, and I think I answered my own question....
The first 2 tips in the pic's are rolled tip service parts, they are not dated but I'm guessing they are from the mid 1980's
The 3rd Tip from the left (Long tip) was shipped from Dearborn to the "Assy Division, Ford Motor Co. , Metuchen Assembly plant" on July 10, 1970 and marked Attn, "Visiting Mfg Engr" so I'm sure it's a production tip.
The last short tip is a service part from 1979
It appears the 3rd and 4th tip match, and the wide part of the chrome tip is about 1/2" shorter than the later pair
Sooo, I'm guessing that it's an early/late service part thing
I'm sure Scott knows this, but just some general info for everyone else
.........
Just FYI, The short side chrome tip appears to be the same part that's welded on the end of the pipe on the long tip, except there's a part number stamped in the bottom of the short tip, and there's a notch cut in the rear edge to index the tip on the tail pipe.
Short side part numbers:
D0ZZ-5255-B , engineering number D0ZA-5C262-C
Long side part numbers:
D0ZZ-5255-A, engineering number D0ZA-5C203-C