Responding to frivilig – to the best of my knowledge the Emergency Service Ribbon was never a medal. The South Carolina NG Exceptional Service Medal uses the same ribbon – that may be what you have seen.
I Own at least one of just about all the DCNG medals and ribbons produced in the past century. Two DCNG medals in my collection date to the 19th Century – there may have been more but I’ve never seen them.
I would be happy to add to the OMSA Images Database. Please advise by email (email@example.com) where to send the images. I assume you wish jpegs of obverse and reverse of each item, correct?