Insulators as follows - actual postage additional:

U-164 -- no markings, crude drippy white glaze, no issues -- $20

U-296 -- no markings, awesome mottled glaze, no issues -- $8 (SOLD)

Small spool with no markings - no issues -- $8 (SOLD)

U-283 (dome incuse) partial Westinghouse logo - great blue shade - no issues -- $8 (SOLD)