This is a very interesting Top Time. I believe it is a prototype or a very rare transitional model between the 810 Top Time and 815 Long Playing. The 810 Top Time's were made using a Venus 178 movement, and the case was unique to the 810. This model is using a Valjoux 7736 however is fitted in a 810 case. In addition, it has the Top Time text printed on the dial, but notice that the three lines on the 3 o'clock subdial are missing, which normally on an 810 Top Time, they have these lines.