No more leaking
Erwin and I picked up some new bungs and stoppers to see if we could stem the leak. When we looked at the barrels, we could see a little bubbling going on. The barrel was under positive pressure! Probably out gassing from the racking, or at least we hope that is it. The MLF is done, and the wine is dry, so anything else (other than out gassing) going on at this point is bad.
We put airlocks on around noon; this evening the barrel is still dry, so I think that was successful.