Detecting over fitting of SVM/SVC
It seems likely that the live data is different somehow from your other data.  Cross-validation shows a 84% accuracy, and accuracy on the held-out set is 86%, which is pretty consistent and does not indicate overfitting.  Accuracy on the live data is 70%, which is significantly different.  That suggests that live data is somehow different in ways that are important to the classifier.  Perhaps concept drift has occurred.