A quality, name-brand modern helmet is rigorously tested and is quite likely safer than your 70's era helmet. Also much lighter, and probably cooler and more comfortable. Current models are designed to self-destruct on impact, but as in Pete's case, most manufactures will replace for free or at a discount. In any case, check for
agency certifications when making your selection. Do a GOOGLE search on "bicycle helmet safety" to get additional info.
Full face protection helmets are available if you really think you need it. And, frankly, what bicycle gear doesn't look funny? We're only used to it!