My question is for our historians about the title and emblem Sting Ray(68) and Stingray (69-?)

Chevy had waaaay more important issues to resolve than whether or not to install Stingray emblems on the '68 cars. I don't think anyone had actually even considered calling the "new" car anything other than Corvette at the time. That decision came after production began.
Print material is always done far in advance, so it may not always show what is actually available at production time. Consider the dealer brochures listed the LS-7 engine as being available in 1970, but none were ever produced.
The Sting Ray/Stingray was just a matter of differentiating between the "old" car and the "new" car.
Corvettes from '69 to early '77 had Stingray emblems. Once the supply was out, someone made the decision to simply discontinue the emblems.

Interesting, I didn't know the early '77s had the emblem - always thought they ended it straight up in '76.  Kind of weakens my argument with my wife about why I should get a 2014: then I'd have the last of the old Stingrays and the first of the new ones!  (But not a big loss - no way in heck of that argument actually working )

EARLY '77s.....like the first couple weeks of production(approx) had Stingray emblems. Story is, once they ran out of them on the line, that was it. 

I purchased a '68 last Nov. which was the C3 First year.

Fascinating looking backwhen they produced these cars, decisions were made like, "We don't have enough Stingray emblems, that's ok when ever  we're out, that's it.  Well that means some '77s will have them and some won't!  That's ok, let's get rid of what we have and they'll buy them anyway............Fascinating!

You have to consider the fact that GM was, and still IS, in the bidness of making MONEY. In the mid/late 70's, they were selling every Corvette they could build. One of the reasons the platform lasted as long as it did was that it worked, and folks were buying them. Emblems or not. Consider the '74 did not have the emblem on the fuel door....the '73 did....the '75 did...why not the '74? Dint have time to fool with them. Busy trying to get the HEI working, as well as the EPA mandated emissions related crap worked out. "Bashes?!?! We don need no steenkin bashes....." 

If the assembly line was close to running out of screws to install say....the rear compartment door hinge, they dint shut the line down...they sent someone out to the closest hardware store to get some that would work. As far as the engineers were concerned, if it fit, and functioned properly, how it looked dint matter. This is why it is soooooo hard to positively state that ALL this-or-that year Corvettes had this-or-that screw/bolt holding this/that part on. Running low on bumper bolts? Send Bubba down to ACE to get some.

It is fascinating(to me) to read about how GM did things back then. There are still plenty of folks around that actually worked on the assy line when our cars were built, and they can tell stories all day about stuff you wouldn't believe.

In the end, it was all about the Benjamin......

On my 72 the battery hatch door has no rubber bumpers. The little circle that should have been punched out to take the bumpers are there but were not punched. On my 66 Dodge Charger one of the bucket seat mounting bolts was air ratcheted through the floor's sheet metal at an angle...completely missing the weld nut under the floor. I guess 3 bolts is enough in case of an accident!