I thought that I'd have wrapped up the basics by lunchtime, but now, its time for tea and the problem is still not resolved. I've got the core of the pixbuf operations working and have now come to realize that this is pretty well a 'package' in its own rights. I see that GtkPixmaps are more closely associated with GtkWidgets and need accessed in order to perform Cairo operations.
My general hunch is that in order to perform manipulate imagery I need to determine just how I to approach each side of the task and to determin what set of lib functions are best suited for purpose.
I need to produce some utility functions that will enable me to rapidly move pixbufs into to pixmaps and then into widget for display purposes. The code that I've add to the gnocl::pixbuf source to address is expiremental at the moment and most certainly will need to be tidied up.