I answered another add on craigslist from someone with insulators for sale. The person who had these used to have an electrical contracting business that did some work for the local utility. Here are the suspensions and arrestors that pulled from a trailer loaded with scrap metal. The 6" bells are 1954 PP Inc and 1955 IEP, and the 7" bells are 1947 Pincos and 1949 Lockes. The arrestors are McGraw Edison 9kv units from 1973 and the fogbells are AB Chance from 1977.