Your clarification as to who this Robert Coste had descended from made be able to locate his file. Since you had replied to my original query about Eugene Coste & Louisa Tims, I had assumed that you were seeking a Robert Coste that was a child of this union.
However, Robert Maxwell Coste was the son of Eugene Francis Coste, and grandson of the original patriarch, Eugene Coste.
I have some of the PDF files taken from the Toronto Star that were published about Robert M. Coste. If you wish them, please send along your email address and I will be more than happy for you to receive them.