Online telephone directory gives 10 Leidenius listings, all in Alberta or British Columbia.
http://www.mytelus.com/phonebook/index.vm

John S. Leidenius from Teuva? Finland served in the Canadian army during WW1. See his enlistment paper here.
http://data2.collectionscanada.ca/cef/gpc009/457856a.gif

The book, Crestmere-Sylvan Heights Heritage, is available online. Search for Leidenius.
http://www.ourroots.ca/e/toc.asp?id=1241