Glad it worked, my pleasure.
The case number, in your case Gxxxx denotes the sequential order in which the case was produced. This can be used to get an approximation of when the watch was made, but not exactly. The numbers are made in sequential order, but cases thus produced are not necessarily assembled and completed in the same sequential order.
Your watch was probably produced sometime in the last few years.
The four digit number is the "number" of your watch in that particular configuration - ROC, chronograph, metal.
Hey, show us some pictures!
"A Purist does not believe in gilt by association. Respect, AND disdain, have to be earned..."