WP #63-A is the Japanese symbol 'Da 田 under a Roof'. The 'Da' 田 symbol looks like a window pane with four panels.
This maker's mark has only been documented on 3 1/2 floats. It has been classified as a rare mark.
Since this float measures almost 5 inches in diameter it could be the only known example of this size to exist in a float collection.
Beachcombed in the Aomori Prefecture, Japan.