[Eliot Ness]

I personally don't think those supports are going to make that much of a difference. Plenty of other radios out there that didn't use those and the grille cloth wasn't blown or sucked out of the cabinet

But if you want to keep things original, and I can understand that, forget the popsicle sticks, tongue depressors, and paint stirs. Do it right by getting an appropriate piece of backing board and make a new one. Either take Kirk up on his offer or send him the dimensions so he can send you a piece to make it yourself.