I know what you are talking about corazon90 - Mom, my grandmothers and aunts - they all had them back in the 1950's but they were metal instead of plastic. I haven't seen one of these in years! I spent a couple of hours trying every search combination I could and I can't find one. It seems that when someone decided to put an electric motor on it and call it a "Food Processor" these hand-cranked versions went away.
Only options I can see for your Mom are:
(1) Rotary (drum) hand cranked grater
(3) Food Processor
Since the clean-up labor will be about the same for all of them - a food processor would probably be easier on her arthritic hands and wrists.
FYI: I looked at the gizmo on eBay that Jim posted and it's a "Food Mill".
"It ain't what you don't know that gets you in trouble. It's what you know for sure that just ain't so." - Mark Twain