I’m in the same boat. I need a reader or adapter for a Powerbook G4. It uses the PCMCIA sized cards. The reader you posted Gary is for a desktop.
I just ordered the Dual Systems Adapter,
https://www.duel-systemsadapters.com/?productid=DP-0002
and found that it doesn’t work with the SxS on a Powerbook. So I’m stuck. I found this by Novatel:
https://3gstore.com/index.php?main_page=product_info&cPath=15&products_id=422
But I don’t know if it’ll work.
Help anyone?