Here are two tough to find stoneware insulators as follows - actual postage additional:

First is a U-1132A from Canada -- likely an early British import! Has a grooved base and is in nice VNM condition with just a tiny peck -- $55

Second is a super early (1870s) Varley Patent 8 (designed for 8 gauge wire) -- these were made in two pieces cemented together. This one is in great shape with a few flakes and a wire rub. The original pin is cemented in but cut off below the base. -- $75 (SOLD)