How to Identify Active Process using Old Process Model Version

Several months back we edited some process models to remove unnecessary notification nodes and it appears there are still a small handful of processes that are running with this old model (still outstanding/ not completed processes). Normally over time these processes were completed and new instances started using the updated model, so at this point there really shouldn't be any old instances still running when there are no associated Tasks to indicate they need to be completed. 

The issue is I cannot identify which process is still running using the old version so I can cancel them or fix them, because the email notification provides no detail (the XML file was deleted thus no contextual data is pulling in). Going through and verifying manually which Record should have an associated outstanding Task would not be feasible so I need a way to find out which Active Processes are running on the old Model version. 

Thanks for any help!