Bottom line, if you care about protection, go modern - nothing from the Skid-Lid era will have the combination of protection, ventilation and low weight that any modern helmet offers. If you care about looks and don't care about protection, get a hairnet and/or a classy old cycling hat and pretend you're Eddy Merckx, Felice Gimondi or the EuroStud of your choice. If you care about both looks and protection, get the modern helmet that fits that you think looks the least bad. If you want a bad look and bad protection, get a Skip-Lid - at least it won't weigh much.

FWIW, I was an early adapter to the 1st-gen Bell Biker, buying it in Fall 1975 (at that time, it was not yet sold in stores, but only available by mail order) after being run off the road by a semi onto a rock-strewn shoulder. I was wearing a hairnet, but by all rights one of the sharp, pointy rocks I landed among should have been sticking out of my head. That instantly sold me on the Bell, even though I had only just graduated from HS and did not have excess cash lying around. I rode that Bell all the way across the USA five years later. It protected well, and the extra "brim" provided by the hardshell outer layer was absolutely perfect for riding head-on into a sunrise, especially when teamed with Ray-Ban aviator wraparounds, but Lordy it was heavy (between 50% and 100% heavier than modern helmets).