Let’s see...
By: KMII : December 2nd, 2018-04:27
Not an easy question but if I take it that you exclude Grand Seiko and Credor from the way you phrased your question, then it would have to be this: The SCVL002 aka 6810-8000. A hand wound, ultra thin watch from 1992, with Seiko’s thinnest mechanical move...