Recently purchased F6516 with Bumper Caliber 344. Waltham 14K Case Just arrived in the mail today. I haven't seen this Reference and Caliber Combination much on the web, only found here. https://www.christies.com/lotfinder...old-automatic-wristwatch-5935325-details.aspx Anyone have further details on why the F6516 and 344 are so hard to find? Is it becasue most refer to the Cal as the 642?