This started with a Uncle Mikes size 14 holster.  I customized this holster to fit my red dot.  The only other option besides fixing this is to buy a much more expensive custom one that might not work because of the V-comp.  It cost $15 and 3 hours to do this but that is only because I can't sew worth a damn.

The Instructions are below.  The tools needed are needle, black thread, scissors, and about a foot of black strap material.  (Wal-mart has the strap stuff for .79 a yard)

Here is the low slung gun belt I made for it.

1. Insert the gun without the scope into the holster.  Push the gun down as far as you want, at least until the trigger is covered.
2.  With chalk, mark on the holster where the tip of the rail is.
3.  Cut the threads that hold the top loop-over and edging in place. 
4.  Next, cut down the sides until you reached the chalk line and cut across to remove the center piece you just cut. 
5.  Cut the top so it is curved on both sides. 
6.  Sew black strap material around the edge.
7.  Sew the edging back.
8.  Cut and sew back the loop-over.