There are over 1300 with the Riddel or Riddell surname listed at Wikitree. Nine of them are named Harvey Riddell. To see the list, go up to the top right of this page and click on Find. Follow the menu down to Surnames.
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I have some Scottish lines but I don't have a Riddell in my database.
If you go to Surnamedb.com , a free site, they have some information about the origin of the Riddel Riddell, Riddal surname. You may want to check it out. The popularity of the Riddell surname is 1719 of a total close to 50,000 surnames.