'Vintage' helmets of the mid 1970s --

The old Bell 'white mushroom' helmet



or a BSR helmet much like a mountaineering helmet,



or a Skid-lid.



A few of our OSU cycling club members wore the leather 'hair net'-style racing helmets...



Would I wear any of those today? no. Not sure what is out there that is 'retro-style' other than the Nutcase and those helmets already posted by others above...