UNSIGNED, THE WATCH MOVEMENTS AND DIALS SIGNED INTERNATIONAL WATCH CO., NOS. 1570467 AND 1570468, CIRCA 1961

According to the Archives of IWC, the movements were produced in 1961.

The cufflink cases were added to a later date and not by IWC. Albeit the cases aren't signed, these cufflinks were certainly made as a special order since the movements are consecutively numbered.