John Mike has provided me URL for the Scottish DNA Project. And pointed you to Ali McDonald the lead Project Administrator. I have been on the team since nearly the inception and am also one of the project administrators. Our suggestion is that your take the most robust Y DNA tests you can afford, with the 67 marker test a good choice. As you are aware of the non-paternal event, you will not be surprised to match surnames other than Boyd or Stewart. This is a great way to bridge the gap in your unknown bit of genealogy. Well worth the fee. Aye, Lauren