I had a great coincidence of meeting Mr. Sinn at Basel show. I was just strolling past Chopard booth and noticed Mr. Sinn walking in the opposite direction. Mr. Sinn is now 95 years young and walking much better than I was managing.
That's a WatchUSeek card Mr. Sinn he holding in his hand
The last time I visited Guinand was in 2006 and he remembered me from that visit (you can search for the Guinand report).
After a brief chat, he mentioned that he has a stock of vintage watches and if anyone is interested, should contact him firstname.lastname@example.org
I will contact him next week and find out more about the vintage watches