Several years ago, I visited a display while traveling to New York. It was in a shop in Manhattan and featured models of working automobiles. Small gas engines, lights etc. All built to exact scale and detail. These were built by 2 or 3 British model makers. Amazing pieces of work that took several hundred hours of labor. Needless to say, the cost was something in the thousands to anyone wishing to purchase one. From what I understand, several were on commission to be built to very rich clients. Anyway, in the booklet that was given out, they mentioned their other models that were available along with cost, ordering information etc. What I recall was one modeler that had both British and German submarines in complete working order. They were 10 to 12 inches long and exact models. I assume that they only ran on the surface and had to have some control device. Does anyone have any information about this? Not that I would purchase one, but would like to read about them. Thank you in advance.