What are the chances of getting emphysema if you have not smoked in 30 years?

Limited. But the answer is more related to how many packs a day and for how many years you smoked (packs x years), also related to individual genetic factors. If you have cough or shortness of breath, see your doctor for a spirometry (breathing test). The test is quick and simple.
Pretty low. If you haven't smoked for a long time, the risk of developing new emphysema is pretty low. But, any damage that was sustained previously will always be there. Whatever lung is lost, is lost, unfortunately.