A little more internet searching discovered a few more facts about my father's time as a prisoner and the men who signed the page in his bible.
Several of them -probably all- were members of the Pudu Fellowship, a Christian group formed in prison. Rev. Noel Duckworth was the president, Rev. Burr Baughman, an American, was the vice president and Alan Kirk, the secretary. I knew the group existed: my father was a member and I've still got his membership card. (Interestingly, after the war he became an out-and-out atheist).
In his book The Naked Island, an Australian account of life as a prisoner, Russell Braddon describes a group of religious fanatics (not to be confused with the Pudu Fellowship):
In Pudu a small group (very small) became fanatically religious and convinced themselves that all ills could be cured solely by faith. Part of their way of life consisted of calling everyone even the most improbable types "brother": part in praying vociferously and fervently at all sorts of unexpected times (during the course of which praying they banged their foreheads on the gaol's concrete floors with thuds that were quite distressing) : and part in refusing even such little medical treatment as was available.
Since they all had ulcers and dysentery, it was a fine point of gaol ethics whether they should be forcibly treated or allowed to pursue their own path of prayer, which on specified dates was to be followed by miraculous cures. When the cult showed no signs of spreading it was generally accepted that they were entitled to their own point of view. And when a month, later the last of the small group died (the requisite miracle on the appointed day having failed to materialize), religious fanaticism vanished forever from prisoner-of-war life as I saw it.
It has been suggested that this was a description of the Pudu Fellowship. This is certainly not the case. Quite a few members of the fellowship survived the war. Not only this, but accounts of the doings of group members hardly tally with Braddon's description - in particular, the stalwart behaviour of Rev. Duckworth, the leader of the group, and a man who Braddon considered to be one of the two most inspiring men in the prison. There was very little paper to be had. When fellow prisoners asked if it would alright to roll their tobacco in pages torn from the bible, Duckworth told them that it was alright, so long as they read the page first! He invented a fictional intelligence contact who -everyone thought- relayed him positive news about the war. He was evidently a strong character who helped keep many of his fellow prisoners going. Before the war, he had been cox in the winning Cambridge boat in the 1934 boat race.
When my father returned home after the war, the Sleaford Gazette covered his experiences with that unintended irony so typical of British local papers:
The article which follows is an improvement on the crassness of the headline, and is perhaps the best account I have of my father's wartime experiences (click to enlarge):