Vintage Baby Buggy NOT Stroller

I'm looking for a baby buggy NOT a stroller. Would prefer one from the early 70's which converted to a stoller but will consider all from 1950 on. MUST be in very good condition or able to be put into such condiditon, as it will be used to walk new grandchild next summer. Brand and color not important. Would like to keep the price around $50 or less but will consider higher if it's just what I want.