Duncan Lumsden, Thanks for your inquiry. Although Ireland is out of my area, The House of Lumsden Assn of Scotland has a Lumsden Clan Sennachie [Historian] that maintains Lumsden information worldwide, and he [Archie Lumsden] might be able to assist you.
You can reach Archie at email@example.com
By the way, we have 40 Lumsden men that have submitted to DNA testing, and Archie is the Administrator of the Lumsden DNA Project. We would love to have you join us?