I-tunes has an old recoding of Nansi Richards playing this on
the Welsh triple harp. It's the Edward Jones 1802 version from
his "musical and Poetical Relicks of the Welsh Bards", which Bill
Taylor plays on bray harp on "Two Worlds of the Welsh Harp".
Although this doesn't directly relate to the clairseach, I post this
here because it's fascinating (at least to me) to hear how
interpretations of the very old harp music can be so wildly different.

Anyway, her recording is on "Brenhines Y Delyn / Queen of the Welsh Harp"

- Karen