The discussion about the two types of filler boards/panels came up in another thread and in turn the retaining hardware used for the early Masonite board based on car assembly plant. Went through my pictures and came up with examples from each plant so thought I should share what I found
Dearborn used a hex headed screw with a large intergrated washer style
Metuchen used a Phillips headed screw with intergrated washer style
San Jose used a Phillips headed screw with intergrated washer style
