The varieties 463h/ha were made from the same electro. variety h corrected a weak band running across the unit resulting in the sails being weak or missing. The extensive recutting to correct this so weakened the plate that a crystalline fracture subsequently developed, which zig-zags across the main-mast and sails for 4.5mm resulting in variety ha.
The latter is scarce.
Variety 463h - The recutting is seen on the bottom left stamp from the main mast and sail to Flinders right eye
Variety 463ha - The crystalline fracture can be seen on the bottom left stamp, zig-zagging across the main-mast and sails