The stuff we mixed up was dumped into the sewer. I saw them do it. I don't think they intended us to see that, but we hadn't quite left the property when they did. Too bad, but there wasn't much else they could have done with it.
Woodford Reserve Distiller's Select (standard sour-mash Woodford) doesn't have an age statement but they always say it's seven-plus years old.
As for the 1838 Sweet Mash product, they did a batch in 2002, but they didn't like how it turned out. This batch was done in 2003, so it's five years old. Don't hold me to that, I'm working from memory. You'd think I'd write things like that down, wouldn't you?
As for the old days, like in the picture. They mashed and fermented in those tubs, like the one pictured, that were actually a little bigger than a 53-gallon barrel, but then when they finished fermenting they went into the beer well to go into the still so, no, they didn't make one barrel at a time. For one thing, one barrel of fermented mash would make only a fraction of a barrel of whiskey, because what goes on in distillation is concentration, from about 10% alcohol after fermentation, to 70%-80% alcohol coming off the still.
I have posted a little bit more about this product, which is here