If anything, the second statement would actually come first - between 1914 and 1920, to be precise:
I read that as...
From 1914 - 1920 the Circle were looking for Oranbega so dissapeared for a short while.
When the 1920s came around the hedonism allowed them to perform dark magic rituals to help them find Oranbega
In 1933 they claimed they had found Oranbega and disappeared in the tunnels beneath Paragon City.
Because they had an unknown base location beneath the city it became hard to put them down.
In 2002 when the Rikti began digging beneath the ground the Rikti ran into the oranbega which made the Circle zealously take them down and claim oranbega
This makes the most sense as if they had already found oranbega they likely wouldn't have had a resurgence or kept looking for it or even bragged about it waited so long to try to raise the city.
one could also argue that they did find the 'entrance' as in they found the tunnels to Oranbega, but had no way of getting in until the Rikti came along.
Also note that it mentions that the "hiding magic" apparently didn't work on Rikti tech. This also denotes that it was still hidden and was not found till after the Rikti... other wise, why wouldn't the Circle just rehide the city?
Another line that is just plain wrong:
1930 - Paragon City, date estimated - During this decade, the Freedom Phalanx wages a successful war against organized crime [26]. Some of the old families result destroyed.
The Freedom Phalanx hadn't formed yet, and Statesman was finding the well at this point.
edit: That's another style thing actually they do form in the 30s, but the specific date is known and it is mixed between decade and specific year.