Yep, 186-191xxx is a batch of 1153s in more or less that configuration. At that period, Tachy scale could be either type, movement is correct. The one thing that would surprise me with a serial in that range would be if it did indeed have first execution hands (polished steel with black line), but the revised hands do seem to come along later for S dials than N so not impossible. A photo would make it much easier to tell.