Looted Maya artifacts which flooded the art and museum markets over 40 years ago, led to two expeditions to Guatemala to determine their origin. The similarity of style was similar to Calakmul, and looters had referred to the location as Site Q, an abbreviation of que. The first expedition was led by two Harvard arachaeologists in the mid-90's. Their info is listed here:

http://www.archaeology.org/online/news/la.corona.html
http://www.archaeology.org/online/features/siteq/

This week it was announced, that a Yale expedition confirmed that the location of La Corona/Site Q is the origin of the looted artifacts.
http://www.yale.edu/opa/newsr/05-09-27-01.all.html

The links have some photographs of some of the tablets that were recovered. It was mentioned that 675AD, is the dating of one of the tablets.