Flat ribbon wire tie developed to "prevent chafing" of the line wire. This example from a telephone carrier line in Northern California
Typically this sort of tie is found on 128's, however many of these carrier lines had what was called a "pole pair" on a crossarm..... the pin positions on either side of the pole. This wire pair was not suitable for carrier, didn't need CD 128's, so glass such as CD 154's, 152's and 121's were found on the pole pair. I'm guessing your Hemi 16 was used as such, and had the same tie as the other carrier glass.
I believe the flat ribbon tie wire on your Hemi 16 was developed by Bell Telephone engineers about the time open wire carrier systems were becoming more advanced, late 30's early 40's. According to a 1942 Bell System Technical Journal article, the flat ribbon tie was designed to prevent "chafing" of the line wire due to wind vibration. Other developments of the time were "low loss" CD 128's, short-thread steel pins and 8" pair spacing on crossarms.
Here is the [id=362327144; similar tie on the CD 121].