Grumley was known as the man when it came to doing all that work to a high degree of skill. Those guys did have access to the best quality material so they weren't wrestling with character staves and thin rings.
They did quickly switch to a more mass production technique as demands rose and that meant using woods like lemonwood or Hickory which take the board bow style very well or backing Osage and Yew with Hickory, Silk or Fortisan to speed up the process and eliminate the need for ring chasing.
The Old Hic bow showed clear evidence of being made mostly by bandsaw.