What Did Buffett Buy: American Express or Wells Fargo?

After Buffett teased the investing world Friday saying he bought more of either Wells Fargo (WFC) or American Express (AXP), folks are speculating as to which one he bought. I was under the impression Buffett and Bekshire (BRK.a) had virtually tapped out their ability to buy more American Express shares.

After buying 13% of the outstanding total, in 1995 Buffett agreed to the following in a letter to the Chairman Harvey Golub. The letter said Berkshire would not:

(1) acquire or retain shares that would cause its ownership of
American Express** voting securities to equal or exceed 15% of the amount outstanding (if at such time Berkshire Hathaway has a representative on the Board of Directors of American Express as allowed by section 4 hereof), or otherwise acquire or retain shares that reflect ownership or more than 17% of the amount outstanding;