If you look on the OA website, it gives his exact location in the cemetery.
Perhaps if you email the cemetery staff, one of them, or a volunteer, will go take a picture of Uncle Monroe's headstone and send it to you.
My Uncle Tom (my father's brother) was killed in WWII, Yeoman Third Class, United States Navy. He was 22 yrs old when he was killed.
His ship, the USN USS Meredith, was sunk by the enemy during the Battle of Guadalcanal.
The ship was carrying supplies to the men fighting on the islands, part of a large US Navy convoy. US military reconnaissance planes spotted a huge enemy bomber group headed towards the convoy so all the ships turned back, except the ship my uncle was on. The captain of the Meredith said that the US marines on the islands were in desperate need of supplies, it was life or death. He refused to turn back and sailed on. The Meredith was sunk in a matter of minutes, despite valiant fighting.
My uncle is officially listed as Missing In Action. There was no body of course, no remains, no burial, no headstone. No nothing. My poor uncle just floats out there in the ether.
(There is a general plaque or something at the American military cemetery in the Philippines for all of those Navy personnel lost at sea.)
We still miss him and drink a big toast to him at every family reunion. My father never got over his brother's death. (My father was career Air Force and flew combat during three wars, so he understood combat deaths. He just could not handle his brother's death.)
So yes, to your uncle Monroe, and my uncle Tom:
Rest In Peace, you are always in our thoughts and not forgotten.