Here's a Blue and a Light Blue U-2421 porcelain insulators from Canada.

The Blue one has a tie wire residue mark and some light use marks otherwise mint for $40. Color is very close to the first one posted on NIA website.

Light blue is VNM (has 4 teeny tic marks and some minor scratches, base has surface factory made cracks not considered damage that are solid) for $20.

8.40 postage for the first one (if shipped to USA, otherwise actual cost). Thanks!