I did a search and I saw great pictures of some of these radios. They are
just incredible. I notice that they often came with a panel on the back
side that came up. I wonder what that was for?


If you are talking about the tube type from the 1950s that panel
lifted up from the front and was a cover for the radio dial to protect
it as well as a holder for the wavemagnet antenna...
I have an H500 from 1952? or so that I should restore one day....
If your talking about the later solid state ones, I have no clue.