Just looking at Trees coat of arms. McMullen? My GG Grandfather wasn't a traveller, but was a McMullen or McMullan. He was a shoemaker from Ireland.
My Traveller's were Todd, Drummond, and Anderson. My families have shown as potters, muggers, stoneware merchants, basket makers, Chapman pedlars, licensed hawkers, tinsmiths, and in Ontario a horse trader. For a lot, I was able to find children's birth records, but the families obviously moved about a lot because of various birth locations. However, there are very few marriage records, so they may have married within a group.
I don't really know if mine had a home base, but it seems they probably did. On my GG Grandmother's headstone it says "of Perthshire", and that's not where she was born. Also, it seemed my GG Grandparent's encouraged their children to be educated, and I'm pretty sure one was educated at Perthshire.
I don't know if there was Romany influence in my family or not. My reading about Traveller's and Romany's indicates they probably travelled in different groups, but there was some intermarriage. My family seemed to move around the border and in the Lowlands. I have also read, that a lot of people had to "take to the roads" as a result of the after effects of the Battle of Culloden, when many were thrown off the land.
I may never know for sure, so I try to study all possibilities.
Thanks!! Tom McMillan (Washougal, WA, USA)