Glad you liked it.
I'm starting to get suspicious of the humidimeter accuracy. There shouldn't have been anything that went out to you at greater than 70% and stabilized down to 70% in the 6 months you've stored them after receipt. Probably a neat toy. Your call if you want to remove the cello and dry box the second sample. Take a measurement immediately and circle back on it daily for a new test. Science!!!!!!