Chanel bags from 2009 onwards no longer are gold plated. So newer bags will not have the gold plating CC mark.

Here is something I found on TPF about the changes in flap bags models over the years:

Chanel changes their classic line periodically but not often. Here are a few examples ------

For Cruise 2011, the classic jumbo flap and maxi flap will have an extra interior flap like the reissues.

For Fall 2010, the caviar classic medium/large flap lost the extra thread line that runs along the border of the outer flap.

After the initial introduction of the maxi flap in 2008, for which wings quickly developed upon use, the style was completed changed to resemble the shape of the jumbo classic flap. The overall shape of the maxi went from slouchy and boxy to a more structured and rectangular shape.

Around 2006, the classic jumbo flap went from square shape to rectangular shape.

In 2009, the GST went through a drastic change. The lining changed from grosgrain to stain like material. Other changes include the appearance of the outer CC logo so that the stitchings do not show and engravings were added to the grommets.

In 2008, some CC hardware were changed from flat to round. Around cruise 2009, Chanel changed it back to flat, and then in 2009, they went back to round. Also, the 6 point star screws were introduced in 2008 and used in some bag but not all.

2009 marked the end of gold plating.