TC25-350 BLOCK PLANE. Mathias Mayo. Mayo is best known as the guy who improved the Phillips patent plow, but he also manufactured these block planes, which are far more rare. 8-1/8" sole, pivoting lever cap with an ornate "M" on the cap screw (like the plow planes), replacement Stanley cutter with J mark. Significant overall pitting and rust. Rare. From the collection of Harold Unruh. Good 300-600