I ran a search on www.google.com and found a book, "Memorial of Rev James Shaw Sillars . The Earnest Evangelical" , for sale at the web site below.
http://www.gowanbooks.com/book_search/item.asp?bookid=772

Also, check out Brian Lawson's execellent site:
www.lawsons.ca.

There is a listing of a wiil for a James Shaw Sillars on Lawson's Will page.