I've been half wanting to make one for years.
That hands video is fascinating, had it downloaded to the laptop, great to watch again and again, especially the making of the hardware that the kids were assigned to do.
Been holding onto some spruce from skipped piano soundboards for the job..
Haven't come across any builds on the official luthiers forum, but that might be worth a shot to have a search for also.
I seen what I think was the Brian Boru harp in the national history museum in Dublin years ago, tall as myself it was,( if that's what it was,)
it was only there for a short time...
Absolutely baffingly stunning work in that place, how they made some of the stuff must be lost arts, free to visit BTW
I believe the Brian Boru harp is close by, on view in Trinity college, never went there to see if I could get in the door, bit of a posh place for a hairball like myself, but I think it may be free also.
That might just be the penultimate design, not that I have any knowledge on the subject.
Sorry I can't be of any help
Tom