Indo-European telegraph line served as a trans-continental line from 1870 to 1931. Of course some hardware had to be re-placed during this long period of service. An interesting fact is that among the replacement insulators there are both standard insulators (I mean Russian and German standard insulators sometimes called "cylinderheads" here) and replicas of the original ones. Below are some insulators of the original shape.

The left one seems to be one of the original insulators installed in 1869-70. The middle one is a version produced by Matthew Kuznetsov's partnership in 1900. The right one is of an unknown origin (may be an early one, too, judging by the color of it's porcelain).

It's kind of a mystery why they produced these replicas. "Cylinderheads" are superior in terms of wire fixation and there's no problem in installing them on old Indo-line's pins. But there's still a solid reason for making replicas. Indo-line used some wire fixation hardware that was only compatible with these insulators. See next picture.