They can also be found here.
I've also got some signs for Speedup and Sunrise- Get them below (click on the pictures to download) Note- These are edited screenshots to fit advertisment signs in Speedup/Sunrise.
Mashed sign Part 1 Mashed sign part 2
The 'Mashed' sign is in 2 parts. Part 1 is the top half of the picture and Part 2 is of the bottom. When you are placing the signs in the editor, Part 1 is the top sign skin and Part 2 the bottom sign skin.
All the files should be copied, not unzipped into *Sunrise/Speedup install folder*/Gamedata/Skins/Any/Advertisment/