Just opened my game after night and found lots of elders had been made which I had expected but there are four who are masters in three jobs but have not been made Esteem Elders. The three are all masters in Farming, Building and Research. I closed the game and saved a copy of of the log file (its over 900 pages). Re opened the game in case they had been made but no. I have 51 elders so far.
Anyone got any ideas?

50 is the limit for Elders/Totems. As you have seen, it's possible to get a few more, but those are exceptions. You won't be able to make any more by your own efforts.