Technically highest 7 Wonders score
I believe I can get to 231 using the restrictions of the OP, being a 3 player game and only the Leaders and Cities expansions.

Wonders used are Byzantium (A) West, Babylon (B) You, and Roma (B) East.

A summary of the points are:

Military - 16 - from an Age II Stables

Coins - 27 - finish with 82 coins from neighbours purchasing from you, Gambling House&amp;Den and coins from chaining through Vitruvius Leader

Wonder - 3 - from first stage on Babylon (B)

Civilian - 6 - from Age III Senate

Science - 110 - 5 sets, 11 greens + Spy Ring to copy the 12th, Multis from Babylon Stage 3 and Scientists Guild and 1 more symbol using Courtesans Guild to copy West's Leader

Guilds - 27 - all from Gamers Guild (coins)

Leaders - 42 - 15 from Aristotle for 5 sets and 27 from Midas (coins).

The full log of what is played each turn and how the money flows is in the picture below. Hopefully there are no mistakes, however happy to get corrections and/or improvements.

Enjoy! Brett.