SparrowHawk is company owned and operated by Hawk (Tony). One of SparrowHawk's greatest products is the "full" Dummy Selector Kit for the M14 type rifle. This dummy selector kit is outstanding and gives each M14/M1A a new level of authenticity... although this device is passive and cannot be made to function as a "full auto" selector, it makes the USGI type stocks more authentic in appearance! This is truly outstanding!!!
These kits can be mounted on wood or synthetic stocks.
So, if you have a stock with the selector cutout still there, this is probably the best alternative and will give your rifle a real "authentic" look!
Hawk's web site can be found at http://www.sparrowhawkm14.com.