My tank has been expanding, but until now has been annoying, but not cosmetic.  This morning i walked into the garage to see two large deformations/bumps.  So bummed out.

Getting to a dealer is going to be a major PITA for me.

I am based in the Waltham area.

Any suggestions on the nearest / most helpful dealer to contact to get in line?

Look up Riverside Motorsports in Somerville.  I'm getting new brake/clutch levers installed there this weekend.  I'll post a review.

I had a bad experience with the service department at Cycles128 in Beverly, but YMMV.

I had my tank replaced at Eastern. Now of course it is part of Cycles128. If you call Cycles128 I would try to speak to one of the service techs. I will say this.... I think Cycles128 is trying their best to satisfy the Ducati community. Their parts department has been exceptionally helpful to me in ordering different parts for my track bike. I can't complain at all about those guys.  I have not been in for service so I cannot comment on that part.

I would highly recommend Riverside Motorsports in Somerville.  They installed my new Pazzo brake levers (which are sweet) in 10 minutes and didn't charge me for the labor.  They were awesome!