In 1940, Rikhi Ram Sharma began to learn sitar making from Sher Mohammad and Sher Mohammad’s son, Mohammed Maksud Ali (Usef Mohammed Ali), at Sher Mohammad's shop, where he met Mohan Singh.
In 1943, Kartar Chand Sharma and Hansraj Sharma (Rikhi Ram Sharma's nephews) joined their uncle and Mohan Singh at the Sher Mohammad shop, where they made sitars until partition in 1947.
Sher Mohammad and his family, including his three sons, moved from Amristar to Lahore in 1947.
In 1948, Sher Mohammad & Sons opened its small shop in Bansanwala Bazaar. It's main competitor was Bombay, Music. The shop had about seven employees, in addition to the family, until about 1970, when business fell off. Sher Mohammad's son, Zia, took over the shop following the death of his father and two older brothers.
As of 2011, Zia's son Imran was helping make sitars at the shop and son Kashan was becoming involved in the business. At that time, they were making both student and professional instruments that were sold without badges in shops outside of Lahore. Imran and Kashan's four brothers were not involved in the business.
There is a reason that early sitars made in the shops of Rikhi Ram and Mohan Singh are so similar. The have common DNA: the 1940s workshop of Sher Mohammad Sitar Maker.
Today, all sitars from that workshop are of historical importance in our opinion.