Matching Michigan and Borders RUNCIMEN?

Next lornahen webpage update will include a link to the geograph picture of Wanton Walls on the place pages. Which activity was prompted by an early morning phone call from George RUNCIMAN ex of Wanton Walls in response to a letter I'd written him. (It was a welcome call, but it was 5:30am, I hope I sounded coherent). I was trying to find out if there was any further information to be had about the Michigan link and the current whereabouts, if any, of the letters between the Michigan and the Wanton Walls RUNCIMEN back in the 1850s-1870s(?). George was convinced that they were related, and added a snippet, to be verified somehow, that the original Michigan lot had been transported following deer poaching in the Edgarhope forest (appears on maps as Edgarhope Wood, just north of Lauder).

Given my current interest in DNA testing and genealogy, wonder if any of the US lot and the Scottish lot would be interesting in comparing dna to "prove" this? A 37 marker test comparing 2 male line surname descendants showing identical or close dna matches apparently have a 50% chance of sharing common male ancestors within 2 generations, and 95% chance within 7 generations, this latter would cover current day family back to known ancestors on the Scottish side, and likely ancestors on the American side. I can spot several Scottish candidates, but Michigan line descendants look a bit thin on the ground unless I do some more research. The last known male descendant of William (still a RUNCIMAN) that I have records of died in 1981, and the last I have down from James isn't at the address I had for him any more.