File location for the T C4 indicator

[monstermega10]

I was looking around in the C4 weapon and entities files but I can't seem to find where the T c4 indicator is located. Could it be in a folder separate from the C4?
Im looking into adding the T c4 indicator into the other ground placed weapons as well, such as the deathstation or land mine.

EDIT:
I found a code for this but it doesn't seem to work. I am not experienced at all with coding and so I have no clue what this error means. Other than that line isn't working.

[ERROR] gamemodes/terrortown/gamemode/deathstation.lua:5: attempt to index global 'v' (a nil value)
  1. fn - gamemodes/terrortown/gamemode/deathstation.lua:5
   2. unknown - addons/ulib/lua/ulib/shared/hook.lua:105

function DrawDeathStationMarker()
	local Texture = surface.GetTextureID("ttt/flashon")
	local width, height = surface.GetTextureSize(Texture)
	local screenpos = v:OBBCenter():ToScreen()
	
	if !LocalPlayer():IsTraitor() then
		return
	end
	
	for k, v in pairs (ents.GetAll()) do
		if IsValid(v) and v:GetClass() == "ttt_death_station" then
			surface.SetDrawColor(255, 255, 255, 255)
			surface.SetTexture(Texture)
			surface.DrawTexturedRect(screenpos.x - (width / 2), screenpos.y  - (height / 2), width, height)
		end
	end
end
hook.Add("HUDPaint", "DeathStation", DrawDeathStationMarker)

[IMG]http://i.imgur.com/lvprfIE.png[/IMG]