Revolutions is your best bet for Morgan hire in Scotland. The Scottish Morgan Club visited Orkney for a long weekend in May 2013 and it was a very "Morgan Friendly" location - I counted only one pothole during our time there! We were invited to join the local classic car club for their tour of the island on the Sunday and, as it is an annual event, you might find that it is taking place while you are there.
http://www.orkneycommunities.co.uk/ORKNEYVINTAGECLUB/

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