The fact that Gravel & Gold’s URL could be read, rather morosely, as “Graveland Gold,” produces satisfied grins on the faces of Cassie McGettigan, Nile Nash and Lisa Foti-Straus, the twenty-something friends who co-own the new Mission District boutique that specializes in home accessories and vintage clothing. “It’s a little dark, but it seems to be an awesome name for a vintage store,” says McGettigan, a Virginia native.