I have a fuel leak on the leading edge of  one of the left wing.  the leak is around a rivet and has previously been repaired.  There is a hairline crack around the rivet.  I know you have to seal the tank from the inside to stop the leak but I also would like to repair the rivet area on the leading edge cosmetically.  I am looking for ideas to do this.  Is it ok to add a piece of metal (aluminum?) and bond it over the rivet area?