Garry's Mod and L4D2 Issues

I got Left 4 Dead 2 which has both content from it and the first game and mounted it to Gmod. How come only the L4D2 content port and not the other content?

Is there a solution or a patch that adds the L4D content included in the game?

Also, what do I have to do to mount the L4D/L4D2 maps to work properly in Gmod.