buzzing strings

[news.knox.net]

I am working on a console that has buzzing strings; one in the next to
last double string bass and then the next two three strings unisons have a
buzz the third string.  The sound board is laminated and shows evidence of
deterioration right in back of the bass bridge.  Someone had put a wooden
wedge back of the area.  When I mute the right string of the 3-string
unisons the buzz goes away.  Would wood treating epoxy in the area of
deterioation help this? Many
thanks.  Jim Dally