It looks like the rims will clean up, but then then again, I am only looking at pictures. This isn't the fancy race bike that we BikeForum C&V members usually like here, but a perfectly good town bike, errand runner, sturdy and reliable bike.
Knowing a bit about your knowledge and experience, this will be interesting. Sun Ringle seems to have shifted their priorities away from making the CR18 for 26" x 1-3/8" in favor of more popular sizes. There may be other alternatives, especially if you are willing to order from the UK. Perhaps Toronto is better ISO 590 territory than the US right now.
Please keep us updated on the project @
Dan Burkhart .