I have recently come across the grave site of Walter Dredger and his wife Charlotte. It is located on Long Island NY at Saint John's/Trinity Episcopal Church, 1142 Broadway, Hewlett, NY. It appears that they are buried on the Schumacher family plot.
I believe Walter is from the Dredgers of Pearsall, NY now know as Lynbrook, NY. The grave yard contains many Pearsalls and also many Hewletts as inboth the town's name sakes.
The gravestone seems fairly new, perhaps the church office can give you some more additional information on the grave.