Both of these are second / later generation threadless CD 731 No Embossing which were found on the Central of Georgia Railway telegraph line. Next to the CD 728, the CD 731 was a fairly common threadless style for Georgia. All told, I found maybe 12 to 15 threadless and most of them were either CD 728's or CD 731's. All the threadless I found were on "threaded" oak pins. It's likely they were moved from an older line - maybe on the same telegraph pole - in order to replace damaged threaded insulators. I've never measured, but I think the threaded pin must have been bigger or almost the same size as the threadless pin hole. I say this because the "threadless" insulators were all very tight on the threaded pin. Only a CD 731 Tillotson had any material in the threadless pin hole - the rest were all free of any foreign material and it was just glass to wood.