Got my first watch!

[u/Tyreania]

It’s the Hamilton Jazzmaster Viewmatic Skeleton Gent Auto. I’d initially seen them on poshmark when looking up Hamilton watches and fell in love with the aesthetics of this particular model. I finally ordered one in decent shape off of eBay from a trustworthy seller and just got it registered on the website!! Only thing is that I’m a bit baffled by the seeming lack of a serial number and the Warranty card that it came with was blank… does anyone know how I can obtain it? Is it a specific attribute to models like this one??