Some other results with my hand-coloured experiment.
The picture below is my first mistake... the oil I use to moist the surface before applying the pencils soaked the picture and left quite a few marks, interestingly the spots were visible only on the day after. On top of that, I though I'd try fixing the colours with the polaroid "squedge" emulsion that comes with the 55 type film but the fixer not only vanished the colours away but also left more marks .