Four tough insulators as follows - actual postage additional:

U-1818 Italy (ear inkstamp) GINORI - VNM - cemented brass thimble -- $15

U-2060B Italy (crown inkstamp) Verbano crown logo in a triangle -- VNM -- $20

U-2406A New Zealand -- Possibly British make -- holes in the ears to hold the wire -- VNM -- $15

U-2061B Spain -- no markings - small wire groove flake - $20

Or take the set of four for $60