I have the Statistics ROM for the HP-9810A and the associated keyboard overlay. I can include a PDF of the manual as well. I'd trade for some magnetic cards for the same calculator.
[EDIT]
How many cards? I have a few--would need to verify. I don't have very many. May take a day or two; stuff packed away.
Let me know how many cards, so I know when to quit looking. These are genuine HP 9810 cards--they are blanks.