Really sorry to hear about this rip-off and to realize that I was right with my concerns. A similar story happened to me around 3 years ago, when someone offerend me a similar set.
Back then I did some extensive research in order to find out whether it was fake or not. So for similar future events, here's what I always look for when something "rare" is offered:

- Is there a demo of Cadillac Man offered? That happens most of the time, but it just wasn't recorded. The band was on tour, probably wrote it there, rehearsed it before a show and played it a few times. Due to problems with the movie company in the end they never went into the studio to record one.
- A duet with Alice Cooper on House of Fire. That song was written by Desmond, Jon and Richie and just passed on to Alice after BJ didn't put it on New Jersey (most likely by Desmond). They weren't in the studio together.
- The Ballad of Alice Cooper. In an interview around 1990 Jon said that he had written it for fun shortly before playing it on radio. At that time there wasn't much contact with the band and so a studio version (especially coming from some New Jersey session) is highly unlikey, as well as a duet with Alice on that song.
- Demos for Blaze. Surely there are some earlier versions (like the Blaze of Glory take with Aldo that they rehearsed at his house), but I doubt there are many outtakes. It was written in a short period of time and I vaguely remember Jon saying that he made around 10 songs and they were the album in the end. Also keep in mind that he called most of the musicians into the studio (like Jeff Beck or Elton John) and they laid down the tracks there. There weren't a lot of rehearsals beforehand - ergo not many rare demo outtakes.
- Take #3 or #5 etc of songs that we know. How should these persons know which take a song is coming from? Even IF they leaked if highly doubt that someone like Obie would've provided detailed information (especially since the BJ camp doesn't seem to have them all the time either).
- Pre-versions of known songs with different names which usually stem from another line of the chorus or the verse. We've known demo versions that were later on changed into song for the album - Water Into Wine, Revenge, The Right To Walk Away - none of these lines even appear in the song anymore.
- A 15-20 minute version of Dry County. David and Richie explained how Jon's original scrap of the song was a 3-minute piece and how they, as a band, fought him over and over to extend it up to ten minutes. So it was extended, not cut short.

I really hope you can work out a way to get your money back!