Button type thing or...?

[qaela4]

Testing my Tesoro with MAXDEPTH settings as my yard has gotten stingy with signals. Ended up about 14" down when all was finally out of the hole. It included 6 nails, this weird little button like thing, it was one piece but the bottom kinda fell apart. .
Also got this little copper/brass piece that flares out a little about half way up and this little lead(I believe) piece that weighs 4.4oz and was all the way at the bottom of the hole.

 

[danimal03]

it is a 'ball button'. it is old. but hard to tell the exact age since the back is gone. my ballpark age is 1850's-1880's. nice find.