The original intent of the design was to serve as a spark arrestor. Unless yours is made from S/S, there is a potential for it to rust/corrode adding more junk to collect in the tank.
With current gas pumps being grounded through the hose, static sparks are not the problem they once were when the A was originally built - Back then most pumps were gravity fed and not properly grounded.
Bottom line, if it isn't fitting properly or hits the fuel gage arm, you would likely be better off to return it - Creates more problems than it solves.