Do you know the parents or siblings of Dr. Wood? Any further info would be very helpful in this search.
I did locate an article regarding his birthday celebration.
In the Monessen Daily Independent , dated Sept. 8, 1941 Monday, page 3, it states:
Pennyslvania's oldest practicing physician, Dr. George B. Woods, of Washington, celebrated his 91st birthday yesterday. Claiming that he received enough honors last year when Waynesburg College graduated him with a baccalaurate, Dr. Wood desired no formal observance.
ALSO - have you contacted the California Historical Society? They may be able to assist.