Just guessing here, but I believe the #17 bike is a 700cc or under. I know they were looking for a couple 400s to sleeve down to ride the 700 and under class. The other bikes are 650s, of course.....likely with a little NOS. Mike Ortis is the artist that built the bike that Canaberg found the pics of, very nice work indeed.
I don't remember his name, but a another berg hillclimber from Montana posted here a while ago with a Youtube video link of last years Glen Helen climb