Ron,
<<  If I shut of the fuel. Discharged a 2.5 pound bottle in the air
stream  around the cowl openings. Would this from your experience have a
chance at putting out the fire?>>

I finally had the opportunity to run some numbers using the 360 as a
baseline and found the chance of success with a 2.5 lb bottle to be very
slim.  At cruise speed, there is no way to maintain the needed
concentration for any significant length of time.  Slowed to 80 kts,
with a metered discharge rate, you can only get half the duration I
would consider the bare minimum to even have a shot.   A better approach
might be to put the emphasis on detection.  I suspect that most engine
fires are not detected for some time since the airflow naturally carries
the fire underneath the plane and out of view of the pilot.  If the
engine keeps running, melting floor board may be the first sign of
trouble.
Chris Zavatson