The Nov Scotia Song Collection lists the copyright address as Broadband/Quality Music, 467 Church St., Toronto. Ont.
This is probably the same old address that you have. The book makes no mention of any D. Skilling.
It seems that Dave Martins lives in Grand Cayman, Cayman Islands.
Allister MacGillivray may be of help to you because he probably still forewards royalties to him from the publication.
Sea Cape Music Limited
PO Box357
Sydney, Nova Scotia,
    B1P6H2