Complex sentence: It was an offshoot of Rack Rite Distributors, a subsidiary of his father-in law's Lehrman & Sons which Alex Grass launched in 1958, that rented and stocked racks with health and beauty aids in grocery stores.
Split into simpler sentences: It was an offshoot of Rack Rite Distributors, a subsidiary of his father-in law's Lehrman & Sons which Alex Grass launched in 1958. The company rented and stocked racks with health and beauty aids in grocery stores.