I'm looking at bidding on Sinn at auction later this month and I have some concerns. The Sinn 140 I'm looking at definitely has a Lemania 5012 but the dial is unlike any Sinn 140 I've seen before. The auction house says it is from 1990. It has what looks like a yacht timer dial and differently-shaped minute counter hand: I'm worried its a franken-Sinn with a case from a 140 and a movement/dial from a 143. Here's a Sinn 143: And here's what I would expect a black Sinn 140 with a Lemania movement to look like: Thoughts?
My guess is that the dial and hands are from the 143. But it's just a guess. Movement photos and caseback photos could certainly help solve the mystery.
Hard to say. Sinn might be able to help you with pictures. Sinn played around and tinkers with small changes and doesn't always update the public name of the watch.