Robert (MPandC) recommends as tight a gap as possible, which minimizes shrinkage and warping. But that looks like a good start. Flatten (planish) those dots and then zap more dots between them.
Jerry, Those flanging tools are available from Harbor Freight or Eastwood, just plug in an air hose. They do reinforce the joint, but can't really be made invisible like a good butt weld can be. Maybe Lugnutz would be OK with that, since he's going with "patina". Also susceptible to rust between the layers.
