This is fascinating - especially that you might be have some Viking blood! As of now, I do not know anyone else who has done this DNA test, though I know quite a few Gums. Did you have to pay for the test?
This past year my book, "From Tennessee to Oz - The Amazing Saga of Judy Garland's Family History, Part 1" was released.
The earliest Gum that I have definitly confirmed in the line is a Norton Gum who showed up in Knoxville before Tennessee was a state. There is another Norton who ended up in IL which people often confuse with him. This same line of Gums immigrated to central TN and then some went to Missouri and Texas and eventually other places. The stoy handed down to me is that three brothers came to the US landing in Delaware. The early ship records are usually hard to confirm... you have to go through them ship by ship. SOme are online now.