Welcome to the forum.
An intriguing post indeed. I have had a good trawl through the records and there is nothing jumping out reference Pannells or Pammells scouts. As for the drawings by Master Sturgeon, I couldn't link a Lee Buxton carbine, Pannells sword or the 12 time repeating pistol. It may be possible they were his comrades during his naval service? For example, Buxton's Lee Metford or Enfield rifle with his (Sturgeons) Bayonet.
You mentioned Mafeking and Baden Powell's scouts. There certainly was a Mafeking Cadet Corps. In fact the Sergeant major Warner Goodyear was their leader aged 13. In relation to Mafeking, Master Sturgeons last 3 sketches could pertain to the above, the machine gun and the cycle were certainly used at Mafeking. The young cadet Corps transported messages at first with donkeys, unfortunately the donkeys were required later on in the seige as a valued food supply. They were replaced by bicycles. Looking closely at the Armoured car sketch, it could be possible he has added what looks like train wheels at the rear? This could be a crude sketch of the Armoured train which was also connected to Mafeking. I did have a look at the medal roll for the Mafeking cadets, unfortunately there was no Buxton or Pannell mentioned. The only medal roll I found ref F O Sturgeon was as you have mentioned for service in the 1906 Natal Rebellion, where he served in the Natal Service Corps.
Apologies for lack of clarity regarding your request, the above are just my humble thoughts.
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