I agree. But the ATB spec IS punch card stock. Picked
for all the reasons you listed. They make lots of it.
I would love to be proven wrong, but I do not think that is true
anymore. I think the stock spec changed in the 1980s when the magnetic
strip was added (which might be enough to screw up old card handling
anyway). The IATA says that no more stock is being issued (and that
news is from 2008!).
--
Will