Final report...
Elbow arrived... wrong part. Removed the old elbow cleaned it out... not serious muck... cleaned the hoses...again no muck to speak of.
Removed the hose from the sea cock and wiggled a screw driver in there until a good stream of
water came out.... hmmmm was there some restriction there?
Fired up the
engine and the flow is now fine.
I think it was a clogged seacock / strainer.
Thanks all!