Alan,
I've just spoken with Gerard who made the master of the figure about the missing belt (martingale). Following his research, it was possible to wear it under the coat by two slots located on each side. This setting was used when the soldier is equipped with his webbing. Normally the first job of a gunner is to remove its webbing for free movement, but without putting the martingale back outside of his coat. This explains why you don't have a belt on the figure's coat.
Regards,
Pat