Lines are from polishing, the date, mintmark and maybe some lettering (difficult to tell from photos) are suffering from split plating and beginning stages of zinc rot. Spend it or kiss this one goodbye.
I'm not convinced. Die polishing wouldn't affect the devices, and the coin doesn't appear to have been polished. Can linear plating bubbles ever look this clean? Agree with zinc rot on the date and MM, not seeing any split plating doubling.