Yes, there are advantages. The correct drivers can provide color compensation and other custom features that are valuable if you do graphics work and need true color representation.
Gateway doesn't make anything. It just rebrands Taiwanese stuff and charges you extra.
Use the utility mentioned above, though if it's really old the monitor may not have an ID in it.
Option 2 is to check the labels on the back. Sometimes it will mention a manufacturer and model. If not the last resort is to open the case (with the monitor unplugged) and look for manufacturer and model in there. Not recommended unless you know what you are doing.
A long shot is email Gateway and see if they can provide the model info or the drivers. They should have drivers at least.
Ep, glad to see you come back and tidy up...did want to ask a one day favor, I want to enhance my resume , was hoping you could make me administrator for a day, if so, take me right off since I won't be here to do anything, and don't know the slightest about the board, but it would be nice putting "served administrator osnn", if can do, THANKS