The “cheap toys” we brought back from Betelgeuse is how we learned the Thunderbird’s secret of course.  In examining the tech, we realized it had the same base as the tech the Peloran use.  Two thousand years of divergence of course, but that tech is real unique.  Once you know what to look for, it’s impossible to hide.  The Thunderbirds and the Peloran got their tech from the same source.  The Albion.  It was easy to figure out the truth after that.