I too have the 686 PC. I changed the front sight to a red fire sight. and replaced the grips with a set of Altamonts. It has a very smooth action, no further enhancements needed.
Our Mill was located by water, so we always had a problem with gulls. One day one of the guys was going between buildings and a gull dropped a huge load into his big bushy red beard. I think he dropped enough "bombs" to sink a battleship.