Given the ship's numbering it must have been made before the production of the R-99 Last Dancer. The tragedy must have been great enough to have the Space Corps lock all the details of the ship (from planning to low rate initial production) from the public, eventually leading to outright denial of ever building it. Over time, details must have leaked out and the ship lives on as an urban legend.
I really like the sleek design of this ship though. The bits must have been scrapped for engine output too.