Try the Reserve Officers Association (www.roa.org). They also have a Facebook Page. The ROA publishes a bi-monthly journal which may have an inquiries - looking for lost buddies etc. - section. If so, you might consider posting the photo, along with what info you do have - his name and year of service, and see if that stirs some memories. Their member assistance contact is Tracey Ware at 202-646-7733.