A very rare cartridge indeed. SAEC are high-end Japanese tonearm makers, but back in the 1980s and 1990s they also released a line of high-end cartridges, comparable to anything coming out of Koetsu or Fidelity Research at the time. These were made for them by Excel, a deliberately not-famous maker of OEM cartridges which has emerged from self-imposed obscurity only in relatively recent times with their own cartridge brands, notably Hana at the lower end (un-flashy but great value for money) and the sublime Etsuro Urushi at the other end gong up to £20k and beyond for their Gold model.
The C1 was their original take on state of the art and is certainly closer in performance to the Etsuro cartridges than the Hana. I also had Kilian at Holistic Audio check out this one. He said the line-contact tip was in perfect order, but again the suspension needed adjustment as it had drooped slightly and put the stylus at the wrong angle - small suspension part replaced and the mechanism adjusted, it’s all in top order now and playing beautifully. This one comes with stylus guard and inner and outer box, altogether a vanishingly rare package especially in this condition.