Here is a mailing address for you to contact Gabriel. Please note that it is through an agency, so every single letter may not get to him (letters that are simply three pages of "I LOVE YOU I LOVE YOU OH MY GOD YOU ARE SO HOT WILL YOU MARRY ME..." are not the ones that make it through). A response is iffy as well since Gabriel is not very good at replies (he did ask us to pass along that he appologizes for that). Who knows, though. Maybe your letter will be the one he does reply to...
Gabriel Damon
c/o The Tyler Kjar Agency
5116 Lankershim Blvd.
North Hollywood, CA 91601-3717