They are joined by James Johnstone - a member Glasgow Warriors elite development group.
Scotland will open the penultimate leg of the HSBC Sevens World Series, the Emirates Airline London Sevens on Saturday 21 May, a week before the Series climax and international party lands at Murrayfield in the last weekend in May, where the Scots have reached successive cup semi-finals in 2008 and 2009 and won the Plate in 2010.
In the London leg, the Scots will take on Series champions Samoa in the 10.30am tie before lining up against defending cup holders Australia (1.58pm) and completing Pool C against Canada (4.54pm) to determine their fate on day two.
In Edinburgh they will face another tough assignment in Pool D of the Emirates Airline Edinburgh Sevens where they will face Pacific Islanders and renowned sevens specialists Samoa and Fiji, as well as Series regulars USA on day one (Saturday 28 May).
Scotland 7s squad: Tom Brown, Struan Dewar, Michael Fedo, Graham Fisken, Colin Gregor, Fraser Harkness, Peter Horne, James Johnstone, Lee Jones, Stuart McInally, Scott Newlands, Scott Riddell, Ross Samson, Andrew Skeen, Jim Thompson, Andrew Turnbull