My apologies, cg_* variables aren't in the file I'm thinking of. Here is a section of the diff from my build queue slowdown mod (src/game/g_main.c). Playing around with this should give you most of what you want. 
Index: src/game/g_main.c
===================================================================
--- src/game/g_main.c   (revision 2048)
+++ src/game/g_main.c   (working copy)
@@ -74,6 +74,8 @@
 vmCvar_t  g_minNameChangePeriod;
 vmCvar_t  g_maxNameChanges;
+vmCvar_t  g_buildQueueSlowdown;
+
 vmCvar_t  g_alienBuildPoints;
 vmCvar_t  g_alienBuildQueueTime;
 vmCvar_t  g_humanBuildPoints;
@@ -196,6 +198,8 @@
   { &pmove_fixed, "pmove_fixed", "0", CVAR_SYSTEMINFO, 0, qfalse},
   { &pmove_msec, "pmove_msec", "8", CVAR_SYSTEMINFO, 0, qfalse},
+  { &g_buildQueueSlowdown, "g_buildQueueSlowdown", DEFAULT_BUILD_QUEUE_SLOWDOWN, 0, 0, qfalse  },
+
   { &g_alienBuildPoints, "g_alienBuildPoints", DEFAULT_ALIEN_BUILDPOINTS, 0, 0, qfalse  },
   { &g_alienBuildQueueTime, "g_alienBuildQueueTime", DEFAULT_ALIEN_QUEUE_TIME, CVAR_ARCHIVE, 0, qfalse  },
   { &g_humanBuildPoints, "g_humanBuildPoints", DEFAULT_HUMAN_BUILDPOINTS, 0, 0, qfalse  },