Though the idea that tea tables were produced as pairs during the middle of the 18th century in America has been rarely touched on by furniture historians or cultural institutions – the marketplace has preferred and promoted the idea of a singular prestigious object – one of the earliest American references to the tilt-top tea table form are two recorded together in the probate inventory of Captain George Uriell (died 1739) of Anne Arundel County, Maryland. Captain Uriell possessed “two Mohogany Claw Tables” valued at £3.3. At £3.3 these were not heavily carved tables and it’s likely they had plain rather than claw feet. But as they were inventoried in a single listing suggests they were similar in form and may have been ordered as a pair.
See:
In Proportion to the Trouble 
Fascinating about tea table and pairs.
I have a question regarding the Stevenson tea tables. Have you been able to examine the tables and if so did you find any “X” markings on the bird cadge block and the two cleats.
I do not recall seeing “x” markings on the “bird cage” boxes of either of the tables. Although I did not unscrew the cleats of either of the tables during the examination, I have many times found “x’s” on the bottom edges of the cleats and under the cleats on the bottom surface of tops of other tables used to identify cleat placement. Although it is difficult to know whether the marks were made during original construction or during a later restoration, so many of the marks appeared to me to be consistent with the original 18th century marks used to identify furniture elements I believed the “x’s” were stamped during construction. They seem too consistent and similar to have been added by random restoration shops.