I had bought a couple bottles from him. Met him in St Louis. Talked on the phone. I never realized that CALDIGR2 was him. Strange.
He was only in his 60's. I know he dug a LOT over the years and hit a lot of ash. I'm wondering if he smoked and if his illness was cancer, since it sounded like he fought whatever it was, for a while.
I keep hearing about diggers who are supposedly healthy (eat right, don't smoke, etc...) getting hit hard.
I agree with all of the above. It's been my experience that many medicine bottles don't have any exact "dates" on the bottom of the bottles. The numbers and letters you are seeing would pertain more...