I think the figure I saw for the 1910 era flatbed presses was around 800 sheets and hour.
There's a reason the rotaries killed off the flatbed presses so quickly.
The ones we had I think could run about 4000 sheets/hour.
The new ones.... 15000/hour up to 21,000/hr!
And remember, they were doing around 8 colors plus the backs, and there had to be some drying time in between, so figure about a week and a half from blank to finished cards IF they used multiple presses because I can't imagine changing the stone on a flatbed that size was a quick task.
ALC and Hoe were pretty close, Hoe had some rotary typeset presses that were multi color and fed from a roll of material. I have to really organize my thoughts and write them up, but there's a bit of evidence that a 2 color press was used. Which is really interesting because supposedly the first rotary offset litho press was invented in 1910.
Hoe wrote a book mostly self serving in 1902 covering the history of presses, mostly the ones made for typography and newspapers. Those were much faster.
https://www.gutenberg.org/files/6354...-h/63545-h.htm