obviously somebody adjusted the crap out of the pkg brake cable adjuster. Now it's badly rusted and it'll probably be a ***** to adjust back to normal setting. The adjusters at the wheels need to be fixed, first. If you can't get them to work properly, you could put in manual adjusters and crawl under there and adjust them by hand every couple of months. But I don't think many people would follow up on that regularly.
First, make sure the longer brake shoe is in the rearmost position on each backing plate. You need to work the auto adjuster cable by hand and make sure the pawl is contacting the adjusting teeth properly and unscrewing/advancing the threaded adjuster. If you can't make it work properly by hand, there's probably something wrong with the brake install. Consult a service manual, if you have doubts about the spring anchors, and/or locations.
Normally, if the brake shoes are adjusted to the drum properly, the emergency brake will work fine in the as delivered e-brake cable adjustment.
