Wow such community.
Thanks all for the replies, with a lack of a good mailing list reader I have to reply generally or top post so forgive any confusion that might come from this.
My original post was a feeler to see if anyone may have been successful in creating a pdf in CMYK colourspace straight out of inkscape using ghostscript/monshiner, instead of the extra step in Scribus.
Chris they insist on CMYK because the inks used are C=Cyan M=Magenta Y=Yellow K=Black and the plates they use are separations of/to these colours/inks.
Gez, I know inkscape doesnt really work well for a purely CMYK workflow, I knew that from the start. I must say that your statement about CMYK values tied to press settings are not what I, nor anyone I know in print and design have been doing, maybe your statement would make more sense(for me anyway) if you mentioned that printer ICC profiles are tied to specific press settings.
Even so, thanks all for the responses I'll have to continue using the ICC linking method in the mean time.