At some point, some stores in the U.S. found that if they imported
radios or cameras from the Panamanian or Singapore division or agent
of the manufacturer, rather than buying them from the U.S. division or
agent, they could save a substantial ammount of money.

Giving the ICF-2001D a different model number in the U.S. and Canada
(ICF-2010) was an attempt by Sony of America to undercut this practice
of gray market imports. They also sued some of the stores but, IIRC,
they lost in the U.S. Supreme Court.

1) ICF-2001D's made for a certain country may not be able to receive
frequencies that violate the law in that country.

IIRC this applies to Saudi Arabia, Italy and Germany.

(On the other hand, you can't legally buy scanners in the U.S. which
receive cell phone frequencies but you can buy them in Canada if U.S.
customs doesn't catch you.)

2) ICF-2001D's may contain different accessories than ICF-2010's.

Frequently, this is a good thing - the power supply may work both on
110 V and 220 V whereas the 2010 power supply only works on 110.