We can't help if the number isn't correct.
There aren't any 6XX prefix guns,, nor are any of the suffix's a 4 digit type. ALL Redhawks will have at least a 3 digit prefix,, and it was started at 500,, then the suffix is a 5 digit number.
Now,, if your gun is a 502-45xxx,, it would have been made in about 1988.