Stone slacks, leather cardigan, pale denim – who wouldn’t want to dress like Alan Partridge? This may be dad brand clothing, but it announces you as the most confident man in the room. Driving gloves? That’s nothing. Try removing your coat and jacket then leaving the driving gloves until last. That takes guts, or failing that a complete lack of personal awareness. In other words it takes a Partridge. Steve Coogan co-created and has played sports-journalist-turned-chat-show-host-turned-DJ Alan Partridge on and off for 22 years. Nothing his character wears is random. For costume designer Julian Day (Berberian Sound Studio, Rush), working alongside perfectionist Coogan on Alpha Papa must have been a…