That is pretty definitive. If you have metal shavings on the fuel filter you have issues. Those came right out of the fuel system via the return lines. Missing on one cyclinder is a dead injector, the massive amounts of white smoke could be one or more gone.
Likely what happened is the CP-3 is eating itself up and spitting metal into the injector and return system. The black on the filter is normal,m it is just wax and content form the fuel, metal is NOT normal.
Time to pull the injectors an CP-3 to have them looked at or replaced.