Sky Mesa puts you back in the shoes of Gordon Freeman. Sky Mesa is a little map pack for half life that has 4 new playable maps. There are no new weapons nor enemies in this mod. (There are some new textures though.) Just the same ol'half life weapons. There is however, a cameo from an unused HL1 monster.
Here's a CD tower prefab i got from snarkpit.com. I put this in Luther Johnson's office room. NOTE: I took off the restricted sign from the prefab becuase it had an interference with compiling.