My reason for asking about submarines was that the Trident company was an outlet for two model makers. After many years of working together, the older man stopped making new models and the younger man carried on under the brand, "Trident Alpha". Many of the models cast with T numbers had been made by Trident Alpha before the branding was changed and the castings were labelled as TA. As new moulds were needed over time, T267 became TA10267 and so on. Oliver, at Sammelhafen, has simplified his system to ascribe due credit to the individuals who made the models with the benefit of hindsight. Most of the post WW2 submarines were made by the modeller who went on to make Trident Alpha models.