Kraft, thank you for the links, the software is especially useful for another LCD project I am working on where the graphics card in question does not willingly respond to custom resolutions.
I will have a proper look at the circuit diagram soon however I cracked it, albeit a black and white image just like M Pro did on his first try but at least I am getting a stable image of my test machines Windows 98 desktop. Some obvious tweaking is required and like M Pro I need to do more testing and limiting with resistors until I get the best image.
Thanks to Oracle, I had the motivation to go ahead and prove it could work. Okay guys I will keep you posted as to how I am progressing but the key to getting the screen up was good grounding. I managed to workout the circuit board and which wires went where and did what and realized that there is no ground point, its being provided by the input from the PSOne console so I just rigged up a strip board, connected all of the RGB and V/H Sync grounds to this board and then attached the board the ground coming from the DC power mount (the main RGB controller board is using the same point for grounding).
As I mentioned in my original post, the whole thing is such a cheap job that the input/output board is literally falling apart so I am having to fabricate new connections as I go along.