Gunner- JC Higgins was the brand name used by Sears. However, Sears did not make guns. They contracted with companies like Marlin, Winchester, Mossberg, Savage, etc to make guns FOR them- but mark them with the Sears brand. This was also done by Western Auto Stores (Revelation brand) and Montgomery Wards Stores (Westernfield brand). These are known as "store brand" guns.
The Sears Model number may very well be a model 43. THAT cross references to a Marlin 81. Sears gave Marlin a contract for X thousand rifles. Marlin took their model 81 rifle, marked it J C Higgins, and shipped it to Sears.
What we have here is... failure- to communicate.