Anvil, the Canadian heavy metal outfit whose hit documentary has led to a late-career resurgence, is having one the best weeks in its 30-plus year history. The band opened for AC/DC on Tuesday night in Boston - the first of three stadium shows the group is playing with the Australian rock legends; singer/guitarist Steve "Lips" Kudlow and drummer Robb Reiner were trailed around New York City by a crew from ABC's "Nightline" for an upcoming network television profile.