Here's a pair of RARE U-1578 side knob porcelain insulators from England. They are featured on the cover of Worldwide Porcelain Insulators Book. These are quite early insulators (circa 1900-15), evidenced by the "nose" which is glaze welded in place! Hard to find marked examples other than GPO.

On the left is a dome incuse marked Taylor Tunnicliffe & Co. Ltd. Also marked GPO with military arrow. Here's a pic: [click here] Has a match head glaze rough spot on the nose, small scratch on the dome and light use marks on the reverse skirt and wire groove. Steam train smoke in pinhole. 2 1/2" wide x 4 1/16" tall. Easy VNM. No chips or cracks! First email gets it for the generous price of only $225 shipping included (U.S.)!

On the right is a Bullers logo (front skirt) and GPO 2 (reverse). Tiny rough spot on dome, otherwise VNM++. Steam train smoke in pinhole. 2 1/2" wide x 3 7/8" tall. No chips or cracks! First email $250 plus shipping U.S. (SOLD) Thanks!