Bugger - I've got a 1970's copy of the "AA book of the car" which I'm almost certain has a guide to DIY headlamp alignment for the MoT - unfortunately it's at my parents' house and I'm at uni
Any decent MoT place will adjust your lights for you during the test if they're out of alignment, rather than failing the car. Its only a few turns of a screwdriver so they dont charge for it.