I don't know of any company that would undertaking a fiddly time-consuming task like that; I reckon you will have to do it yourself. You can soak the piece in warm water for 10 minutes, and then pluck the hairs out yourself. The soaking makes the hair shafts swell slightly, and the water lubricates the knots slightly, so you should be able to pull them out without tearing the base. Alternatively you can use a chemical hair remover like Nair - dot it sparingly on the knots on the underside of the base. Whichever method you use, do it conservatively, and keep checking the result as you go along. It is very easy to go too far and create a bald spot on your piece, which basically ruins it.