The saga continued ...I found online instructions about refilling the Oem Canon carts by the hypodermic needle method. ie: Showing where the filler holes were and what colour went in which hole.
So out came the needles and JetTec inks, and I refilled the empty carts that came with the printer. Nice simple operation, but don't forget to do it on a newspaper or she'll get mad if you stain a worktop.
Popped these carts into the printer ... ran through the reset routine ... and Bob's yer uncle ... success. And they don't need resetting every time you switch on like the compatibles. The carts are reasonably accessible on an MG2450, so they can be quickly whipped out and refilled when they get low again. Just like I do on my primary Brother printer.
Sorted?? Well no not quite. I can still only download, save, and print the Canon Premium models through the Image Garden software on my secondary PC and its cheapo Canon printer. I cannot yet manipulate them on my primary PC and print them on its A3 photo quality printer. ... But, having printed them to paper I can scan them into it, then print and save as a jpg or pdf file which can be used by any PC or printer. A lot of messing around, but no noticeable loss of quality along the way. QED.
