Phils, Eagles, Sixers, Flyers... are you 4 for 4?
Graphic Designer Wes Kull has created a site he calls "Gridiron League" which envisions an NFL that never changed looks-wise from the Lombardi era. He's got retro style versions of NFL NFL team logo. Here was his Eagles concept.

Gridiron League is a collection of idealized NFL insignias that pay tribute to each team's history and geography in a period-specific aesthetic that glorifies the Vince Lombardi-era over the Cold-Activated-era. This is not an exercise in nostalgia but an interpretation of the league's founding principles through the symbols that we, as football fans, identify with most.