I know this is an older post, but just ran across this and since it is all fresh in the brain.......!
The adjuster arm is a Ford part, common as dog butts....but with the bends taken out of them to be flat. Ford parts have a zig and a zag..... So DeTomaso flattened them and gave them a Pantera only part number that you reference.
If you look at an original, early cars will have an arm stamped D0OE-10145-A and somewhere in 73-74 this changed to a D3AE-10145-A stamped number. The parts books say that the "D0OE" (designed for 1970 Fairlane/Torino models, used in just about everything!) Was used on the Clevelands throughout 70-72. The D3AE version (1973 Galaxie design....) is found on 400's, and they are listed online for cheap..... This design interchanges across many lines and a few engines.
Again, the "Ford" parts have kinks and bends in them and will not work as found. They will need to be straightened using a press or a BFH! (Big Freakin Hammer!)
I can't comment to the design of the alternator mount.