The mounted officer may be part of an artillery set but he or one very like him is listed in one of the brochures as HKP 3.
Yes, there is a very similar mounted Hong Kong Police Officer, but that one has a green and yellow band around his pith helmet. This one is listed as RA3.
Here is the text from the K&C book about these sets:
The "King & Country Field Force" consisted of Royal Artillery and Indian Army Nine Pound Field Guns and Maxim Guns with crews, as well as Indian Army medics attending to wounded Highlanders. The Royal Artillery and Indian Army poses were identical, with the differences being heads with clean shaven faces and khaki pith helmets for the Royal Artillery officers and men, and bearded heads wearing khaki with colored stripes and brown topped turbans for the Indian Army officers and men. The officers stand with binoculars in their right hands pointing with their left hands, or with maps in their left hands pointing with their right hands. The firing crewman stands with his hands held forward to operate the Maxim gun. The kneeling crewman all kneel on their right knee, with their left hand resting on their left knee, and their right hands either holding binoculars, holding a canteen or hanging down by their right knee. The medic was a repaint of the kneeling crewman with the canteen.
The Royal Artillery crews wore the following uniforms: Brown knee boots (officers) or ankle boots with puttees (crew), khaki pants, navy blue tunics, with white belts, pouches suspenders and cross-belts. The uniforms worn by the Indian Army crews consisted of Brown knee boots (officers) or ankle boots with puttees (crew), khaki pants and tunics, brown belts, pouches and suspenders and white cross-belts. The Indian Army medics were attired as the Indian crewmen, but with red topped turbans, and white arm bands with red crosses.
The Field Force sets were: RA1, a Royal Artillery nine pound field gun with crew - three kneeling crewmen and one standing officer with binoculars ($89); RA2, a Royal Artillery Maxim gun with crew - two kneeling crewmen, one standing gunner and one standing officer with map ($79); IA1, an Indian Army nine pound field gun with crew - three kneeling crewmen and one standing officer with binoculars ($89); IA2, an Indian Army Maxim gun with crew - two kneeling crewmen, one standing gunner and one standing officer with map ($79); and IM1 - an Indian Army medic with a prone wounded Highlander (both Khaki and Red coated Highlanders available) ($29).
