This is the 3rd fattie for the MXT this month. I thought it was an 1864 but after washing the dirt off I can't read any date. Today I was using the 6x10DD as my friend and I were checking out several sites I'd found on my 1800's plat maps. I prefer the 6x10 for exploring a field since I can cover a lot of ground quickly. Many times it takes a while to locate a site because the old plat maps aren't that accurate. Once I locate the site I switch to the 4x6DD or the 5.3 concentric depending on how much iron I have to contend with.