The son did reply to me yesterday or thereabouts.

His Father wrote the following publiched books:
"I deserted Rommel"
"New Guinea Crocodile Hunter"
"The Calling Reef" &
"Hoodlum".

Also a triology of three unpublished books. I believe he said these in akin to "Croc Hunter" when Gunter was running guns to anti-Sukarno rebels in New Guinea (or Indonesia?). Pity they aren't published as if they are the equal to Croc Hunter they would be good reads.