I've been toiling with this all night and think I might have one working now.
I'd appreciate anyone who is willing, to test and play around with it.
It is now communicating with the Nochex checkout (which the existing one I had wasn't) and seems to be going OK. Haven't actually performed a live transaction yet only this minute finished it, so can't guarantee anything.

If you would like to try it, click and download the tiny .zip.
http://www.bravo-hosting.co.uk/downloads/Nochex.zip

Any feedback, good or bad would be appreciated. I'll be fully testing it over the next day or so, if it works, it will be available to the community.