Russell was NOT buried in the Masonic section of the cemetery. There WAS no masonic section when the Watch Tower purchased the land on which Russell and other Bible Students were buried.
The Pyramid Monument was not inspired by Masonic belief, but by the belief held by many including well-known clergy, that the pyramid held a divine message. As said above Masonic symbols derive from Christianity, not the reverse.
The Masons kept detailed membership lists and published them. Neither Charles nor Joseph appear in the lists. You are attracted to the myth of Russell's Masonic connection because it - in a way never explained - degrades his work. And none of those believing this myth explain why it would be a bad thing if he was a Mason. Do you in your heart of hearts believe in some Masonic conspiracy? Why?