Here is a picture of my small porcelain Doorbell transformer collection. Top to Bottom: Arrow Electric Co. Hartford CT., Next is an Air-Way Toledo- made by Hart & Haegeman Mfg. Co. Hartford CT., Dongan Ace Electric Mfg. Co. Detroit Mich., Packard Belle Blue- Packard Electric Mfg. Co. Warren, OH, next marked F.C.M.(Fernado C. Messca Co. Irving NJ., Last month Alan Norris posted a picture of a Magic transformer (Magic Electric Co. NY.) This company took over F.C.M and became Magic Electric Co. I hope to find one of these someday to go with my F.C.M. one., After that is a Killark Electric Mfg. Co. St. Louis MO. transformer. Lastly is a RCA (Radio Corporation of america NY.) transformer for radio, bell, etc. Always looking for any porcelain transformers I don't have. Would love to find the cobalt blue Standard marked one. Hope you enjoy these pictures. Take care stay safe and be well to all.