The BBC news article The World's Oldest Scientific Satellite is Still in Orbit talks about the Vanguard program and that Vanguard-1 is still in orbit around the Earth, and near the end shows a photo of Vanguard-3, which survived a launchpad explosion, was recovered, and is now (possibly) at the Smithsonian Air and Space Museum:
According to this NSSDC GSFC NASA Page Vanguard-1 looks like this engineering model:
In both cases, and in the two screen shots above from this old video and this old video it seems to have six antennas pointing in orthogonal directions like the normals to faces of a cube standing on its corner. However, the header for the BBC article shows this instead. What satellite with four antennas protruding from its equator is this, or of what satellite is it a model? Does it represent a later Vanguard design?