large old farm pottery high power electricity supply pole insulators

Set of large old porcelain and iron electrical insulators from an old farm estate. This measures 17" long and about 6" across the porcelain insulators. They are marked for 10,000 pounds each. One of the insulators is marked "82123-7" and the other is marked "82123-10". The iron cable end is marked with what we think is a date "12-37".

We've been told that these are used on the utility poles where the high voltage power lines are brought into the farm for distribution.