I am selling my Sinn 556i rs. the leather strap has been replaced with a new calfskin strap with white stitching by Hirsch - one of the official strap providers used by Sinn. I can include the original strap if wanted. the original buckle with the Sinn logo is attached. The case and the sapphire crystal are both in excellent condition Box and papers all included as from new. originally purchased from CW Sellors in Whitby, an official Sinn UK dealer in March 2021 if you have any questions feel free to ask.
eBay