Parting gifts for Tom ‘OB’ O’Brien after 40 years on the job included a personalized stone tablet, a firefighting axe engraved with his first and final years with Belmont, and a Tupperware container of mashed potatoes. “When David [Jones] and OB were … together, and David’s wife would make food and bring it in, the one request he always had was mashed potatoes,” explained 911 Supervisor Jimmy (James) Riccio. “Don’t touch those,” O’Brien joked as the potatoes from dispatcher Jones’…