As stated by Augustus Lucifer:

Point 1:
The Period of our mod is now: 1180 - 1280 A.D.

Point 2:

Strat Map Wonders AFTER the current start date can also be included in the mod, which opens up a whole variety of Faction Research concerning Strat Map Wonders.

Remember that the later a building is build within the mod, the shorter it is seen by the player.
(For example a building that is build in the year 1270 A.D. is only seen on the map the last 10 years of the time frame)
Therefore it is still the best policy to find buildings build closest to the Starting Date of the mod.

It's better if this is put as a sticky, instead of a post forgotten in some thread.