In regards to why the b/w manual is in an early car...frankly owners manual styles have more correlation (from what I have seen) to the original sell date at the dealership than they do to the serial number of the car. In general and early car would have likely been sold earlier than a late car...but it was not uncommon for any of these cars to be tough sells at the dealer level. For example, the early black car i had not selling from Tasca till August of 68. On the car, it would make perfect sense that Tasca might have already blown through their supply of "produduction" (ie "typical") original manuals and had ordered more for their remaining stock ...hence being sent black and white "service replacement" manuals. There is no sell date noted in the registry for #0023 so its entirely possible that the black and white manual came with the car the day it was sold from the dealer, if it took a while to retail.
In addition, its equally as likely that the first owner could have not gotten a manual or even lost his "production" manual early on and requested another be supplied. Its equally plausible that the replacement could have still been a "standard" manual or the black and white version we are discussing could have been given..just depends on what was available at the time.
Similarly, the only year i have never seen a "service replacement"/"oddball" manual associated with is 1965...but ive heard no shortage of stories from early owners who said they requested a replacement 65 manual because they didnt get one with the car...what showed up in the mail was simply a standard production type 1966 Shelby owners manual.
Anyway, just some possiblities.
Vern