OK, I answered my own question! I looked thru all my older magazines and found an announcement from" Carl Goldberg Models Inc" for their " new shoestring stunter"  On page 42 of the Febuary-March 1961 Flying Models magazine in the "whats cooking? forum. I posted this in case any body else is searching for this.....Gene

 Thank you for the link to Outerzone. When I went there I see they are using a picture I took a few years back of my own Shoestring! Any way, thanks again.....Gene

 Dan, you got me investigating again! I googled" Carl Goldberg " and the AMA biography of him came up. Hers what I found so far,   Opened hobby shop in 1935 and designed the Valkyrie
            After several yrs went to work for Comet as chief designer & designed comet Clipper and Zipper Stayed there 6yrs
            1947 worked under the name of Top Flite produced Zing, Cumulus, Trainer, Rascal, & a dozen Jig time kits
            1955 went into business for himself." Carl Goldberg Models" designed $1.00 kits & Later came Blazer, Ranger, &
              Swordsman. Biography states that Carl Goldberg Models were on there way when he produced the Shoestring.
       
            The earliest advertisement I have so far is the 1961 Febuary-March issue of Flying Models. I'll keep searching to
            try and find an earlier date. I have a friend that has an original kit and possibly there may be a date on them. Any
            one with a more concrete date please let me know. Gene
             

  UPDATE,  I continued looking thru my collection of magazines for any more information that I could find on the Shoestring Stunter, and here's what I came up with. In the 1961 June-July issue on page 28 of Flying Models They did a one page article on a, " look see", " Carl Goldbergs latest offereing", the 42" Shoestring Stunter. It has a picture of the entire kit punched out and an extensive article about it. It also states that Carl "thoroughly designs and tests his aircraft". I take that to say that it has been flown and tested before the kit has been released, which appears to be what the 1961 Febuary-March FM article stated. So, the Shoestring Stunter by Carl Goldberg Models was released as a kit in early 1961....Gene

Thanks for the information.  Getting back into the saddle 2 years ago this was the first thing I built.  Probably had this kit sitting on the shelf in a closet for 30 years  I don't know if this would be a common trait, but wood quality was noticeably superior to either of the Sterling kits Ive messed with since then, including a third Sterling (P-51 w/ flaps) that I looked at and just put back on the shelf, it was that bad.

I had wondered what the vintage of the design was.  Seems it was intended as a rival to the Ringmaster.  Wish it was OTS legal.

Gary