Quote Originally Posted by Balbus
Sorry if this is a stupid question (I'm new to modding), but I can't seem to find symbol for the Senate amongst these files.

symbols1.tga.dds contains the three Roman families, whilst 2 to 5 has the other factions. 6, 7 and 8 appear to be blank. Can anyone help? Thanks.
It's not a stupid question (at least the same problem happened to me at the beginning). I imagine you are not an expert in photoshop (as me ) and you are not familiar with alpha channels.
Some of the symbols are only visible in that channel (germans for example), as they are white.
In the menu open Window>Channels. You will have a new window and your visible (eye on the left) channels are RGB and the individual red, green and blue. Click on the alpha and you will see the senate symbol.

If the problem persists I will try to post some screenshots.
Good luck!