Hello again Kate,
There is unfortunately no picture taken of the guarantee group as they boarded the Titanic in Belfast. However 1 member of the guarantee group, the assistant manager electrical Department of Harland and Wolff William Henry Marsh Parr, was taken on the 11th on the gymnasium on boat deck on the electric horses.
This is his last picture among with Titanic her physical instructor Thomas McCawley.
The Harland and Wolff guarantee group on-board the Titanic when she left Queenstown existed out of 9 men selected by the Thomas Andrews Jr (with him included), they are listed here bellow with their ranks at Harland and Wolff:
Thomas Andrews Jr (1873-1912): Manager of the construction works, director of the drawing office and chief architect of Harland and Wolff (since June 1910) and head of the guarantee group traveling in first class.
Roderick Chisholm (1868-1912): Leading draughtsman of the Olympic class traveling in first class.
William Henry Marsh Parr (1882-1912): assistant manager electrical Department traveling in first class.
Anthony “Archie” Wood Frost (1874-1912): outside foreman Engineer traveling in second class
Robert/Thomas Knight (1869-1912): leading hand engineer traveling in second class
William Campbell (1891-1912): joiner apprentice traveling in second class
Alfred Fleming Cunningham (1890-1912): fitter apprentice traveling in second class
Francis Parkes (1890-1912): plumber apprentice traveling in second class
Ennis Hastings Watson (1893-1912): electrician apprentice traveling in second class
All the representatives/workmen of Harland and Wolff on-board had a complimentary ticket. However when she left Belfast a few more workmen and other representatives of the shipyard were onboard such as Edward Wilding of the drawing offices, Thompson Hamilton the sectary of Thomas Andrews and Joey Thompson who was a painter and decorator meant to give the Titanic a final touch before departing. All of them left in Southampton before or during the departure on the 10th of April.
I hope this may help.
Yours sincerely,
Thomas