City directories, published mainly in the 1800s and first half of the 1900s, are similar to phonebooks and were created for a like purpose—to list people by name, give contact information, and provide space for businesses to advertise their wares and services. Sometimes the directories listed all working adults at the same address and included their occupations.
The 1923 and 1924 Lynn City Directories listed Nathan Gass as the president of Lion Shoe located at 195 Boston [Street?]. No other Gass brothers turn up in these two directories. In 1925, Lion Shoe appears for the first time in the Lynn’s business directory under “Shoe Manufacturers.” The 1925 Lynn City Directory (published in January of that year) identifies Morris Gass as vice-president of Lion Shoe at its new location, 61 Allerton. Samuel Gass is listed as clerk and Nathan as president.  This listing indicates a move to larger quarters and perhaps the involvement of the other brothers happened some time in 1924. This supposition is supported by the fact that Morris Gass didn’t move to Lynn until 1924.
Note: The Lynn City Directories for 1919-1922 were not available.
 City Directories of Lynn, MA, Jan. 1923and 1924 (Boston, MA: Sampson & Murdock, 1923 and 1924); Massachusetts State Library, State House, Boston, MA.
 City Directory of Lynn, MA, Jan. 1925 (Boston, MA: Sampson & Murdock, 1925); Massachusetts State Library, Statehouse, Boston, MA.
 City Directory of Lynn, MA, Jan. 1924 (Boston, MA: Sampson & Murdock, 1924); Massachusetts State Library, Statehouse, Boston, MA.