Oh gosh. I love the way you've written this. You've got the tone and the characterisation spot on. (Especially with Childermass trying to persuade Segundus to be the president and Segundus finding reasons not to.) Many lines made me laugh out loud, including the end. This one was a particular joy, and is very very Childermass:
It was a small, ironical smile that he directed at Segundus quite often during Society meetings, and one that Segundus fancied meant something along the lines of You and I are together the only people here who are not behaving very stupidly.
In fact, I liked the line so much, that I've added it to my own post-book headcanon :D