Sears started as a railroad telegraph operator.
His first business was selling watches he bought by the case and sold individually to railroad workers.
When there was a need to service the watches Sears brought Roebuck, an experienced watch repairman, into the business.
The likelyhood of anything stamped or nomenclatured Sears alone being a legitimate Sears product is minimal, since there is no record of the original watches being marked Sears.