The eBay thing, I already left a positive feedback when I received it, however if they do neg me they're only 100% (32) after 6 months on eBay whilst I'm 100% (502) after 5.5 years on eBay and can always leave a followup reply to theirs and then complain to eBay about the excessive shipping charges & get SquareTrade on the case. I've decided to ignore their email and see what happens, replying to it without paying will probably make things worse no matter what's said in the email. Oops just noticed how badly this is going off topic.

Hmm not a bad idea on the monitor calibration service, just need to find 10 suckers...

I found I installed some program ages ago called "Monitor Calibration Wizard" which adjusts the gamma based on a set of visual settings to adjust, might give it a whirl on both my machines at the same time and see if I can get them to show the same picture without any colour differences.