This insulator is full of tiny bubbles, and has a tiny amber olive mustache inclusion near the bottom of the skirt. The closest embossing I can find is [405], but "Cauvet's" seems to be missing, and there is an extra July 25 date. So it seems to read PAT./ ULY.25.18 (last 2 digits obliterated by a straw mark)/JULY. N. 25 1865/PAT.JAN.25.1870/PAT.FEB.22.1870. I think that perhaps the weird embossing was created by some ghosting. It's hard to photograph because the embossing is faint, but If someone wants to see it, let me know and I'll try to photograph it. Asking $20 plus actual shipping.