Back in 2004 an unnamed Guest asked about preservation of lighthouses: at Kinnaird Head, Fraserburgh, in NE Aberdeenshire, we have the Museum of Scottish lighthouses: well worth a visit if ever in these parts.
www.lighthousemuseum.org.uk

As for “Da Slockit Light” = here is the full quote, in the words of Tom Anderson himself, as to how the tune came about: Tom was born in Eshaness, and even helped with the building of the lighthouse there in his younger days.
"I was coming out of Eshaness in late January, 1969, the time was after 11 pm and as I looked back at the top of the hill leading out of the district, I saw so few lights compared to what I remembered when I was young. As I watched, the lights started going out one by one. That, coupled with the recent death of my wife, made me think of the old word ‘Slockit’ meaning, a light that has gone out, and I think that is what inspired the tune".
(So please play it nice and slowly - it’s a lament, not a march!)