I don't know if your office on the British Island is using European Color standards. In Europe, specially here in Germany, but I think in Britain it is similar, never use US SWAP profiles.
Look here: http://www.eci.org/en/start
I don't know if this will work, but perhaps create this color as a spot color with the current CMYK definition in the US workspace, then in Ink Manager turn on Use Standard Lab values for Spot Colors, and convert the color to process.
The resultant colour is blue (approx C92M68Y18K0).
What preset are you using for the Export, or what are the Output settings? Have you tried PDF/X?
PDF/X-4 will leave color unchanged and profile everything, so a color change like you are describing most likely means the wrong output profile is being used in the UK.
PDF/X-1a forces everything into your doc's CMYK space and makes conversions at output less likely—with X-1a your 80|80|0|0 mix will probably be output unchanged.