The triumphant Borders side had last won in 1925 to add to their 1921 success, but no-one could live with Selkirk on a cold afternoon when they scored 143 points and put themselves in line for the Kings of the Sevens title.
Selkirk led 17-5 at halfway, Scott Hendrie and Nyle Godsmark exchanging tries before Angus Duckett and Callum McColm put the Philiphaugh club in front.
Fraser Harkness, Hendrie again and Gavin Craig settled things in the second half before Ryan Godsmark got a consolation.
Selkirk beat Kings holders Jed-Forest 33-10 in the semi-finals, while Accies upset Gala 22-19. Holders Hawick fielded an inexperienced squad due to their big Premiership play-off match and went out to Hamilton 32-12 in the first round. The Archie Smith Memorial Cup for the Player of the Tournament was won by Selkirk’s Darren Clapperton.