So, pots have arrived, along with an orange cap, so I can start on the wiring, once I've made some corrections:

Original pot on the right, new one on the left. Slight misunderstanding on a) what a mini pot was (I assumed the kit ones were standard not mini), and b) the website describing the length of the shaft as the threaded bit, and me assuming it was the entire length including the knurled top.
Ho hum.
Also in view, cardboard template for the wiring - which I hope to get around to this weekend.