Hi, thanks for your reply.
I contacted Hantarex, but they gave me the same answer of "no, we won't do it as its a health and safety risk"

Thanks for the heads up about gis10p.co.uk, I'll give him a call. I'm a bit more concerned about the H+S issue now, so I'll see what he says. Hantarex actually said they wouldn't even modify the monitor so the degauss happened when the monitor is switched off and on (as opposed to only on cold starts).
I do have a degaussing coil, which is OK, but it never seems to get rid of all the discolouration, there always seems to be a large patch that doesn't resolve in the bottom left corner of the screen.
My only other option, which I don't really want to do, is to swap the Hantarex Polo/3 with a digital arcade monitor that has a manual degauss button that I can tap into. My only problem is that here in the UK I've not been able to find a good digital 21" arcade monitor. Multisync would be preferable, but not essential. Does anyone know anywhere that can supply a 21" one of these to the UK?