I am another of those owners of a manual card punch...
Some members of this list probably have sheet-feed scanners
at least mechanically capable of grouped card reads.
As for the reading software, it could be a snap to do, at least
when compared to what we call standard OCR today.
More down to earth, There is an eBayer up in ?Minnesota?
?Montana? that cornered the market on card readers, uses
a few for himself, and sells the rest.
John A.