Here is an almost new Signet TK-7SU nude Shibata cartridge with a less than 3 hour old TKN-3 stylus from Signet themselves, purchased by me (during the fall of '86) from then authorized dealer Stuart's Audio in Westfield NJ. the actual use is probably more like 2 hours, I never really used it due to having a few other cartridges and then receiving a Shure V-15 type V-MR for Christmas not much after. The Signet body was given to me by a media professional neighbor who had also just purchased a Shure, so this one sat. Yes I had intended to use it, but Shibata styli are a tough setup, and I have no 4 channel records, then or now. So, 30 years later, here's your opportunity to own this.
I have tested it in my current rig, there are no isssues whatsoever. As it was stored in dark, temperate storage with low humidity, the rubber in the suspension has survived perfectly.