The Borgo S.1 with its original iron pin cemented very firmly in place. It would take a long soak in muriatic acid to dissolve the cement (or the pin). Probably best to leave it in place for now.

update 8/30/07: Dave gave me the go-ahead to attempt to de-pin this insulator, so it is now marinating and fizzing in a small bucket of muriatic acid.

8/31/07: the pin, thimble amd most of the cement is now out, another day or two to soak (now in Oxalic acid) and make it all shiny new looking !

Base diameter is approx 6 inches or 150 mm, and the pinhole is abour 1.2 inches or 30 mm. Overall height is 2 3/4 inches, approx 70 mm.