In early 2011 , his grave 's plain granite headstone was replaced with a bronze plaque that lists several of Knotts ' movie and television roles .
Knotts ' obituaries cited him as a major influence on other entertainers .
In early 2011 , Knotts ' grave 's plain granite headstone was replaced with a bronze plaque that lists several Knotts Knotts ' movie and television roles .
Knotts ' obituaries cited him as a major influence on other entertainers .