Hi Demonwolf. If it is not too late for you pay a visit to your local Artist supplies store and purchase some Oil paints such as Burnt Umber Vandyke Brown Florentine Red Ivory Black they all mix with turpentine or turpentine substitute. Have a mix trial and you should be able to mix up a colour to tone in your comb patch to the rest of the stock. Use the edge of a feather dipped in black Indian Ink having diluted it first with water to get the correct black depth to reinstate that dark grain line at the patch joint.
