Mystery solved thanks to three readers who have great detective skills. Chris, Mary, and a reader only known by the alpha—letter combination “gsbo3632” jumped in and found pins on eBay for sale that gave the clue to the society known as the Modern Brotherhood of America (the MBA on the metal grave marker). Turns out the Modern Brotherhood of America was a membership organization founded in Tipton, Iowa, in 1897, whose main purpose was to provide insurance to its members.
Readers coming to the rescue could be called crowdsourcing, which the dictionary defines as, “obtaining (information or input into a particular task or project) by enlisting the services of a large number of people, either paid or unpaid, typically via the internet.” But I call it friends helping friends!
GEO. F.
VAN DEUSEN
1887 – 1910
The metal marker next to the George Van Deusen gravestone in the Woodland Cemetery in Jackson, Michigan, is no longer a mystery.
Gravely Speaking 
My name is Greg Bucher.
Very nice to meet you, Greg. I have checked out your blog and it is well done.
I was able to find a book on Google that explained what FLP stand for with the MBA, it is for Friendship, Love, & Prudence which was the core values of the group.
Below is a link to the source:
https://books.google.com/books/about/The_Fraternal_Monitor.html?id=c4DnAAAAMAAJ&printsec=frontcover&newbks=1&newbks_redir=0&source=gb_mobile_entity
Thank you so much for unraveling that mystery. I appreciate the research.