Was just on the phone with Apple Care for an hour & 3 minutes (1-800-275-2273).... He gave me a link to their website (see below) with power adapters listed (has pictures @ bottom of page). He said the older "T" style adapters are only available for purchase over the phone, so basically you need to go to this page and figure out which is correct for your computer and then call Apple Care for the purchase. (I originally called the Apple Store, & they told me they couldn't help & transferred me & this is the info he has given me). FYI, he said something about the purchase going through "DIY", but never explained what that meant.
(The reason the call took over an hour is that at first he kept telling me the "L" style power adapters are fine for the older style MacBook pro & I had to CONVINCE him it doesn't work. Upon further investigation on his part, he found the way to purchase the old "T" style. Hopefully if you go to this link below, you will be ahead of the game when calling!)
http://support.apple.com/kb/ht2346