So it seems that the linux dedi (app id 17705) been pulled and SteamCMD keeps coming back as "INVALID PLATFORM".
I've tried just copying the game files over from my PC to the dedicated server (running Ubuntu 12.04), then copying srcds_run and srcds_linux from TF2 into the Insurgency folder, but it won't start up.
So this is my last resort. Does anyone have the Linux Dedicated server files? Preferably someone who is running a Linux-based server right now.