Mix butter and crushed wafers and press 2/3 into 2 (9″x13″) pans. Top with 1/2 quart orange sherbet in each pan. Layer vanilla ice cream on top, about 1/4 quart per pan. Place 1/2 quart of orange sherbet on each pan, again. Top with rest of crumbs. To layer ice creams, you may need to soften slighlty.
Freeze overnight. Each pan will serve 12-15.