The problem with the name Peter Gannon, is that it's quite common.

I googled it, and found a Roman Catholic priest ordained in 1901, a dentist, a political aid in NY, an engineer in Montana that passed away recently, a Franciscan Friar that passed away 21 May 09 in Rhode Island, a movie actor, among others.

I'm sticking with the MD theory until I check around town some more.

Glenn