if it hasnt been mentioned the bronze mallard ar on the back of the duck,directly in line with both shoulders.you wont get much half a dozen or so each side.
the cdc will be in the middle of the back,almost an invisible line were all other feathers start to finish.it almost looks like an ace of spades.
weve had some melanistic pheasants on our shoot and ive used some of the feathers from the back close to the leg,very similar to peacock neck for bumbles.
you can also use the neck feathers as you said for hackled wets.
woodcock wings and body feathers for hackles.
also unless your mates spoted them,there are two pin feathers on the woodcock,not much use tying but a nice keepsake.in the shooting comunity youd put these feathers in you hat to show that youd shot a woodcock.
its tips are white along the edge of the wing.
http://www.wildart.co.uk/images/imgmain1/feathers.jpg