Hi Do a Google search for Nelson BC - a beautiful city/town
http://en.wikipedia.org/wiki/Nelson,_British_Columbia
http://www.hellobc.com/nelson.aspx

Salmo BC
http://en.wikipedia.org/wiki/Salmo,_British_Columbia

Chas. is an abreviation of the given name Charles.
eg same as Tom is Thomas. Bob is Robert - Jim is James etc.

Charles A. AUSTIN is your Great Grandfather - born 1863 in New York U.S.A? What is your source of for this information?

What name does the letter A. Stand for ?

Have you searched USA Census 1920 1930 1940?

Where do the alternate spellings of ASTON/ AUSTON ? come from ?

Charles was your Great GRandfather - Where were your Grandparents born, settled etc - Where were your parents born settled ? PERHAPS you can find some connections - through family obituaries etc.
Name of your GGrandmother - etc