Hey Chris,
I know of one example of the 1916 fragmentation grenade with a transport plug that is very similar to the flat brass fixture, with the two holes for the tool, but no hole for the fuse. My reproduction is based on the one in the IWM, but that is the only basis I have for it.
I might point out that the French ball grenade you have IDed as 1847 is the 1914. The 1847 body did not have threads for the fuse, although it had several improvements to the fuse over the years up to WWI, when they threaded the body for the brass fuse, it became the M1914. The M1847 and M1914 are the same size and weight, they only differ in the type of hole for the fuse.
Best
Gus