That's a very unique take on a guitar, Bill ... thanks for sharing. I was very interested in his tuning, which has a higher A at the top, and the lower B at the bottom. His conversation about the A-string "being in the way" sometimes was enjoyable. His musical Irish accent made him a bit tricky to understand at times, but his whole setup is very intriguing.
Many may be familiar with Spanish guitarist Narciso Yepes (1927 - 1997) who created a 10-string guitar which became his signature. The top 6 strings were tuned in standard tuning, while the bottom four were (working downward) C - Bb - Ab - Gb. He never played these, but they were there purely for sympathetic vibration. It added a lot of depth to his sound, not altogether unlike a "Chorus" effect pedal does with an electric guitar.
Thanks for this, Bill ... thoroughly enjoyed it!