Johann "Val" Stokes

I am looking for information on a Johann Stokes who often went by 'Val'. He may have been Australian. Here is what I know about him:

Stokes started his aviation career as an aviator for the United Kingdom during the First World War. After the war, he became a doctor and traveled to Borneo where he did charity work up and down the Kinabatangan. While in the region, he met Martin Johnson as well as Martin's pilot James Laneri. Inspired by the Johnson's S-39, Dr. Stokes purchased an Aeronca kit. When the kit arrived Jim with Martin's permission took a few months off from his duties as the Johnson's safari pilot and helped Dr. Stokes assemble the plane. The plane was assembled at the Doctor's house in Sandakan and test flown in Sandakan harbor. Sadly, the Stokes story ends badly. Dr.Stokes picked the wrong island for peace. Japan occupied Borneo in early 1942, and Dr.Stokes was imprisoned in camps which were known for brutality. After several years of imprisonment he was beheaded.

I realize this is not much to go on. Does anyone know anything more about him?

Kevin Holcomb
www.airminded.net