Crossword puzzle clue "part of many a grid"

Part of many a grid

The 2x2 black square near the middle of this puzzle's grid, e.g., which is part of eight answers

Old rush participants ... or a three-part hint to what can be found in this puzzle's grid or clues

Grid uniform part

Part of a grid team

1967 Box Tops hit about part of a puzzle answer grid?

Many, many, many

Many, many, many