The two truant shop employees are still in there, though they got demoted to the B-plot by the playwright who introduced Dolly, and of course their names changed when they emigrated to Vienna and again when they emigrated to America. In Hello Dolly, they're called Cornelius and Barnaby, and Cornelius was played by Michael Crawford in the film version.

Horace Vandergelder, the man Dolly has set her cap at, is Cornelius and Barnaby's boss, which is why he's otherwise occupied and they have the chance to go truant. (The business with the boss's daughter and her unsuitable suitor which was the reason for his distraction in the original play is down to the C-plot in "The Matchmaker" and almost vestigial though still present in "Hello Dolly" -- and for some reason in the American versions she's become his niece, possibly because somebody decided having a daughter of marriageable age would be offputting if he was going to be the main character's love interest.)