Add/fix undetected or missing monitor display resolutions to X on Ubuntu 12.04

I am using a DVI to VGA converter on my Ubuntu 12.04 machine to connect the graphics card (which doesn't have native VGA) to a Dell 2405 monitor on VGA. The Dell 2405 can handle resolutions up to 1920x1200 however the use of the VGA adapter has prevented Ubuntu from correctly reading the EDID data that the monitor provides, to detect the resolutions the monitor is capable of. At current I am stuck with the highest resolution of 1024x768. Xorg.conf has typically been the place in the past to address these issues however it seems to be becoming depreciated. Here's how I manually added the higher resolutions...