Yeh, it replaced Gunmetal Grey. I had a 04 Gun Metal grey before my Mondeo and I cant honestly tell the difference. Paints4u also said they suspected K51 but I think I will wait until I get the car and check under the bonnet. K51 is also referred to as Precision Grey.
Did the deal on the car on Sunday but it had a little dent in passengers door where some plonker had opened another door on it in the showroom so I have to wait until next week for that to be sorted. It's a 313 GT spec with Alezan leather, no satnav. Love it, can't wait to pick it up!