Here's an somewhat scarce U-1606, a porcelain insulator shown in an 1885 Buller Jobson & Co catalog as EI 509. What makes this insulator rare is that it is incuse marked "ARGENTINO". I have only seen this marking on one other porcelain insulator and it was rare also. Unusual 3/4" pinhole.

Condition is near mint plus with only some wire groove rub marks in the saddle groove and above the wire groove on each side. Some light surface discolorations. No cracks or chips.

First email gets this tough porcelain insulator for only $60 plus shipping. Thanks!