LYNN ? Jim Sherman looks back fondly on the days when his late father, Sam, steered the course of the Brotherhood Credit Union, making certain members were satisfied and the institution solvent.In that regard, little has changed since Sherman took over the institution, which is now celebrating 75 years of doing business in Lynn.”If somebody insults the credit union, I take it personally,” said Sherman, who as president and chief executive oversees 21 employees and more than $106 million in assets deposited in approximately 8,000 accounts. “You could say I’m married to this job, but I can’t help it. It’s in my blood. I sure don’t know what they mean by banker’s hours.”Sherman, who grew up in Lynn and lives in Marblehead, said the credit union’s strength lay in its fiscally conservative policies and longtime relationship with the bulk of its customers, all of whom as members get a single vote at the annual shareholders’ meeting.”That’s a big difference between a bank owned by some huge corporation and a credit union like this,” said Adam Sherman, 31, son of the credit union president and the institution’s manager of finance and business development. “We also don’t fee our people to death and we can often beat the banks on rates.”A Salem resident, the younger Sherman is master of the Mount Carmel Masonic Lodge in Lynn, a bachelor, and the fourth generation of his family to serve as an officer in the credit union. Father and son daily work side by side, just as Jim Sherman once did with his father, Sam, who did likewise with his father, the late Joseph Sherman.Joseph Sherman’s name first appears on credit union documents in 1934, the year it was founded at a Jewish synagogue in Lynn.”We’re not exactly sure where the temple was located,” Jim Sherman explained. “We do know that the credit union was located on Blossom Street, Summer Street, and then on Mount Vernon Street for several years before moving to its present site at 75 Market St. in 1979.”The second story of the Market Street building was added in the mid-1990s and a Marblehead branch office opened in 2006.”We work slow and steady,” said Adam Sherman. “The mega-banks just grew too quickly, went into uncharted waters and found themselves in trouble. We haven’t had a foreclosure in eight years.”Although father and son predict the credit union will expand, radical change isn’t likely. “I’m probably more conservative than my father or my son,” said Jim Sherman, who claims he has learned to delegate authority in order to take time off for ocean cruises with his wife, Judy, to far-flung destinations. “I love to travel but I always worked six days a week. It has been that way since I was five or six years old, running across the street to get the coffee when we were on Summer Street.”Sherman wasn’t always a financial manager. After graduating from Classical High School in 1965 he earned a bachelor’s degree from Boston University and in 1969 joined the Army Reserve. Family ties kept him involved in the business, although he returned to graduate school at Boston University to obtain a master’s of education degree. “I didn’t know what I wanted to do. I actually was a student teacher at Classical, which was a strange experience because it hadn’t been very long since I was a student there myself. I also did some substitute teaching, but eventually I ended up back at the credit union. Even while I was in college I came home weekends to help out. It was expected.”Sherman proudly holds the credit union’s original charter, a stained and yellowed document framed on his office wall, the many signatures of the founders still legible.All the names are of Jewish ancestry. Membership in the 1930s was limited by ethnicity.”In those days, every nationality had their own financial institution,” he said. “Ours was comprised of the brotherhood of the Beth Jacob Synagogue, so the credit union was aptly named Brotherhood.”The original bylaws limited membership to those affiliated with the synagogue. In