Jeff,
Have you contacted the funeral home in St. maries? Your G, Grandfather's place of burial could be on the funeral record. I found my grandfather's burial information at the funeral home in St. Maries, and the funeral record had lots of other information I didn't already have, including the place of internment. There is only the one cemetery in St. Maries, the next one being in Plummer. I checked both and didn't see your g, grandfather there.
Could you contact me direct at lshphrd@shaw.ca I'd like to strategize a plan for you before my husband and I head south.
Linda.