I think I'll leave it at that. What sharpening I did was achieved by using Sennelier Lamp Black in the background at the bottom; and tightening up the pods with my new Caran d'Ache pastels, that will leave a mark on a soft pastel substrate. I must try another painting using these as the main pastel to roadtest them further. The reflection of the dalla was achieved by drawing and rubbing it in firmly before applying the background; then erasing the background to reveal the gold ochre underneath.
By the way, the Sennelier Lamp Black must be the most friable of the Senneliers - it is basically soot mixed with the absolute minimum of binder - there is no way you can use it for detail. And when you make a mark with it, it looks like a grey piece of burnt paper ash sitting on your support until you rub it in and get the black you are seeking.