Totally agree with the letter idea- make sure you also enclose your email address,us oldn's ofetn find that an easy way to correspond

As well as a phone number and a stamped self addressed envelope of course.
Also apologise for bothering him,incase he is the wrong person.
Don't give too much away(but enough!) in the initial letter,if it's him he'll get back to you to find out more.
Carol