I remember seeing the pistols you are refering to on the Colt Webpage and in the catalog. There were two variations of pistols. The most recent rendition were the Tactical I, II, III pistols. These were listed during the FBI SWAT pistol trails, and were variations on Colt's entry in the trials, at least this is my guess. Since you have one with the adjustable sights, the Tactical III, we know that Colt did make some of those. But the other Tactical models may have never been produced, unless a distributor ordered some.
The Special Combat Gov't Model (Carry version) was a blued steel pistol just like you described with night sights. It was offered prior to Colt offering the Tactical pistols. I have seen one, about 5-6 years ago. But it must not have been as popular as the target model since it was only offered for a year or two, while they still make the target model. I wish you luck in finding one, as I doubt very may were made, and the few that were have probably been sold from stock long ago. So your best bet will be looking at your local, or regional, gunshows to see if one is being sold out of a collection or as part of an estate. Did your book of values mention the number produced.
Concerning Colt's marketing strategy, at least their previous strategy. I think they did a lot of what Microsoft does. They would market vaporware, or something that does not exist, to see if there is any interest and build it if they were ordered. Another problem Colt had, was their quality control was not up to what their marketing was telling people. So the distributors did not buy the higher end guns, because the people that wanted high price pistols, bought the base guns to send off to Wilson, Clark, Kings, or the other top pistolsmiths to be customized.
From what I have been reading, in the past 2 years Colt has really improved their quality. So with time they can do more, or at least better, marketing.