Indeed, that's Ed Braley's site and his info was very helpful for me when doing my first conversion.

Judging from the last photo in your flickr set, I'd estimate that you don't have enough clearance between the stays to fit wide 650B tires. Measure the clearance between the stays (and also the fork blades) at exactly 320mm from the center of the dropouts. That's where the fattest part of a 650B tire will be. Subtract from your measurement 5mm and that's the absolute largest size 650B tire that you could fit (and it would be a close fit). Also measure the height of the bottom bracket, on a very level floor with fully inflated tires. Measure from the ground to the center of the crank. If it's less than 275mm, it may end up too low after conversion, and result in a high risk of pedal strike.