Hi Jenny,
The profile manager is an active Scotland Project member and I think you should be able to reach out to him in order to collaborate and add sources to the profile.
I see that you've added the information to the profile about being mentioned in Scots Peerage, but it is important, especially on pre-1700 profiles, to also provide author, publication info, volume, page, and when available, an online link to the source. There's a basic example in Help: Sources Style Guide.
There is a very useful finding aid for Scots Peerage here on Wikipedia. If you scroll to the chart, all of the volumes are listed there, including the index and corrections.
Hope this is of some help to you.