I know this is an old thread but like me i'm sure people are still looking at it for advice. I basically emailed him saying that I'm a Politics student who lives in his constituency and would like to enhance my experiences and gain some knowledge into the working of MPs etc. He passed it on to his researcher, so it may be worth emailing them first and i've sorted a week out in July. I know someone posted about being forgotten but he said to email a couple of weeks before to arrange it so he can sort things for me to do whilst im there.