In the 1999 Product Portfolio, the P210 (9mm Luger) is listed under 'Sport pistols' together with the P229S and the P220S.
That would mean it's still available as new in the USA.
The P210 is not listed in the 2000 Product Portfolio and it's not on their website. Give them a call. Even if they don't offer it anymore, I'm sure there are some out there somewhere.
Sig 210's are listed in inventory in the Long Island Shooting Center's website. Price is $1599 without the .22 conversion package and a couple hundred bucks more with the conversion package. I didn't call to verify whether they had any in stock. Best regards.