Value, any info and is this rare?..I bought this today, saturday at a local auction and never knew these were found around here. It is huge ,14" dia and about 12 inches high.. mint condition too. I started a local man who was a friend of my parents into insulators 40 years ago and he found some neat insulators over the years. I traded him back then, but never saw this piece in his collection..Well he died several years ago and now the wife had a local auction and I bought a lot of my traders I traded him back then in 1970, but never knew where he found this piece...I never seen any of these in northern Illinois.
What it looks like you have here:
is a Locke M-4321, made at the Victor, NY plant. These were listed in Locke catalogs, from 1907 to 1916, and were used quite commonly, on 60kv lines. So, it is definitely an old piece. Checking the value (my book is a few years old) the insulator seems to go for anywhere between $75 to $100. The colorful glaze though, would probably put it at the higher end.