Your bigger problem is in explaining the 101 natural clocks [so far but still going up] that completely contradict your one precious method.
How about you start by exploring the moon as a natural clock. It’s current orbit is receding at a constant rate, so how far back can you go before the tides cover the highest mountain peaks, or better yet before the Earth and Moon orbits collide? It’s almost like something major catastrophe knocked it out of it’s orbit or some such...
When I was a kid, I remember my Dad getting hold of a level that had the vial mis-mounted. When he figured out that it didn't work right, he threw it out and went and got a different level. He didn't just quit using levels.