A formal analogy between sedimenting drops in Stokes flow and a swarm of Stokeslets [Machu et al., J. Fluid Mech. (in press)] is extended to include interfacial tension. Using a cohesive potential, mean curvature is extended as a meaningful quantity off the interface, allowing the boundary-integral formulation to be rewritten in volumetric form. A prescription for assigning forces to the Stokeslets comprising the swarm incorporates the action of interfacial tension without having to identify a boundary surface. Numerical simulations agree with linear small-deformation theory, and reproduce the spontaneous coalescense of two touching drops.