These good doctors will repair or replace zippers on just about anything, from luggage and clothing to tents, sleeping bags, golf carts, and boat and convertible tops. They fix umbrellas, too.

On a cool, drizzly Saturday morning in an open garage at Venice’s Edgewood Nursery, Sal D’Angelo examines the clutch of a broken-down golf cart with the eye of a surgeon. Something isn’t working right ...