I saw that frame on ebay and was real close to trying to win it. It is a unique Sting no doubt about it. From the pics in the auction you can see that Blake is correct in that it's brazed at the head tube and TIG welded everywhere else. I think it is a frame from the transition of the last days of true brazed Stings and the first Predator Stings. It may even be a prototype or team issue frame. I have seen a pic of one other similar frame in the last 5 years but that's it.
A "normal" Sting serial number is a little different than the rest of the Schwinn line since they were built in the Paramount room. Typically the 1st letter is the month code, the next digit is the year (9=1979, 0=1980, 1=1981), the third character is always a T in a Sting (Not Sting Comp) which means Tri-oval tubing, the last numbers are the sequential production #'s
Blake's serial # FTP00009 I think designates the 9th Tri-oval Predator (TP) made. Based on this I would put the date of the bike at early to mid 1982 because that was when Schwinn was phasing out the "true" Paramount style Stings and was experimenting with ways to cut the costs of production with the upcoming Predator line.
Either way, Nice bike and I'm jealous! I was really thinking hard about adding it to my Sting collection.
Here's a pic from the auction showing the TIG welded rear dropout: