Here are the few pictures of Donal Lunny's blarge (oversized 10-string bouzouki tuned CGDAD) that I have been able to find.
I am pretty sure he had at least 2 different ones, one made by Andrew Robinson & Antony O'Brien in Dublin (no longer building instruments)
and one by Andy Manson of Easterbrook, England.
I found a picture of a third blarge, obviously also from Andy Manson but less elaborate. This one was shown in an article next to a photo of Donal, but I've never seen a photo of him "holding" this one. So it may or may not be one of his instruments.