OK, from someone who has done like 20+ cabinets I can say truthfully and knowledgably that a 19" arcade monitor bezel does not, will not and cannot match up to any common computer tube, and certainly not if you don't decase the PC monitor.
My Defender has an framed arcade style 21" VGA with a 19" bezel in front of it, and the bezel blocks a bit of the screen area. It is only acceptable on that cab because it has some serious smoked plexi and you can barely see the bezel.
With your cocktail you are better off just painting your monitor case black and then putting a piece of smoked plexi or glass in front of the tube. You won't even be able to tell that there is no bezel then.