Ladies and gents, this watch popped up in my eBay saved search and for $150, my curiosity was piqued. Any insights, case back number interpretation, etc would be helpful. Maybe my Google-fu is starting to age, but I couldn't find good resources on identifying it. Mainly I want to make sure it isnt a frankenwatch. The crown is probably a replacement and the crystal needs a good polish, but I can't find any other obvious defects.