I _thought_. Turns out it's probably a typesetting/layout/editing error. The information is there; the line in the list of sections is missing.
The theory is straightforward: the missing Peter followed his half-uncle Peter to become a Holdeman Mennonite/CGCM/Church of God in Christ, Mennonite. His first wife was the foster daughter of half-uncle Peter. The second wife was a US Mennonite from the Ohio area (and there's active Holdemans there) whose first husband was an Unruh. The third wife was a US Mennonite from Oklahoma, and I think also from an area with a lot of Holdemans. For suitable definitions of "a lot". The net effect was negative feeling with the rest of Johann's descendants (problem with this thesis: I'm not entirely certain _which_ branch of Mennonite they are, if they stayed KG or became something else and I am so far a little too chicken to contact someone and ask (my primary contact having been excommunicated for quite a while, and is over 80 and I'm not sure what his health status is currently).
That's the theory. It was a great theory. And I found what sounds like a memoir written by Peter, currently in the Glenbow Archive. I've sent them an email to ask them if they will make me a copy or otherwise help me get access to its contents without traveling. It'll be interesting to see if anything comes of that request.
ETA: Sweet! In exchange for a telephoned credit card number, I should be received emailed copies of the document (37 pages, and the pictures are on the website already) soon. Very exciting! In related (ahem) news, I found a T. Family Chronicle, 1900 in Preservings, No. 18, June 2001, page 97. I will probably be quoting from that in a later blog entry.