Jim,
If you go to the Scotland's People site at:
http://www.scotlandspeople.gov.uk/
Bottom left 'Coats of Arms'
'The ScotlandsPeople website provides access to digital images from the Public Register of All Arms and Bearings in Scotland from 1672 until 1907.' No idea how good or bad this is as I haven't used it.
I've used the site for genealogical purposes, there is a charge of course and you gotta register.