Speedo Cable Does Not Spin/Turn

I found the cable had twisted/snapped only two inches from the transmission. The (plastic?) speedometer pinion appears to have survived.

The local speedo shop advised me to purchase a new cable. I asked about repairing this one and the owner said his tool to make replacement inner cables was stolen so he does not perform that service any longer.

I mail-ordered another cable. I have some liquid graphite I am thinking about using for a lube (the carrier evaporates and leaves behind the graphite). I have seen that grease is not really recommended.