1) Ford DID make a diesel option for the Rangers and Bronco IIs from their inception in '83 to 87 or 88. Never seen one in a Bronco, but have driven a few Rangers with the TUrbo diesels- pretty zippy for the time and being a 4cyl TD. I'd even venture to say it'd keep up with a V6 of the time. I think the reason it never saw production in the Full Sizr Bronco was a) light duty front end, and b) lack of demand for a 1/2t that topped 20 mpg. Keep in mind that the diesels of the early 80s were hard to start, noisy, and smoked like chimneys or were GUTLESS. Hop out of your CTD and into an 84 with a (naturally asprinated- need headache relief after towing a load up a hill with it) 6. 9, and you'll see what i mean.
2) WHY, oh WHY in the h@ll do they discontinue a vehicle, only to reintroduce it as a "new and improved" version 5 years later??? T- bird, Impala and Malibu (ok, more than 5yrs for them), come to mind quick.