This is much the same recipe we use for our Luv-a-Duck duck stock. Here's how you can make your own.
1kg duck carcass with skin and fat removed
2 sticks celery
1 large onion
2 medium carrots
1 bouquet garni
200ml red wine
2.5 litres water
You will probably want to reduce the stock down after you have strained it to strengthen the flavours.
So you can have your stock on hand at any time , freeze stock in 1 or 2 cup sized containers. Margarine containers are great for this as they are approx 2 cups or for 1 cup use plastic or paper coffee cups. Pour in the stock Freeze stock until frozen . Remove from the container and place stock in a double freezer bag , seal and freeze until required.