I'm not doing a breeding project, but for winter squash (in Florida) I ran into an old breed Seminole Pumpkin. I ran into it doing some research and started my hunt. I found two starter plants at a local garden show in September '11. One quickly died being in the shade and maybe a little less water. The other one planted six feet away is still growing 12 months later. In the time, it has produced two 14-16 pound pumpkins and three 8-10 pound pumpkins. One pound converts roughly to one cup cooked. I was about to pull the vine out as it takes up over 20 square feet of space, except I found two more of the smaller pumpkins and one that looks like it will become the larger. Further inspection shows at least 2 more female flowers.
The best thing is that I rediscovered (as pointed out by research) that these pumpkins will last at least five months once picked. Then you freeze the remainder once cooked, even more time. We've been eating roast pumpkin, pumpkin/ potato mash, pumpkin bread, and even pumpkin cookies regularly since January.
Here's a link to an article on Seminole Pumpkins
http://www.eattheweeds.com/cucurbita-muschata-seminole-edible-2/