What they mean is that most commercially produced roses in the US are raised in California and for decades the practice there was to graft roses onto a rootstock. The rootstock used more frequently than any other was an old, once-blooming dark red climbing rose named Dr. Huey. Sometimes the tops of grafted roses die. When that happens dormant buds in the rootstock will often come to life and instead of whatever the original purchaser had in mind, there is the climber Dr. Huey. They will probably bloom in following years (as long as they get enough sun, water, and nutrients), but they will only bloom in June because that's what Dr. Huey does. It lacks the genes necessary to bloom in flushes throughout the summer.

Here is a site that may help you ID the bloom. Here is a link that might be useful: gallery of blooms

It looks like Sweet Chariot... do the blooms fade as they mature?

Childscapes, on this forum you can start your own separate thread. That might bring you quicker answers. There are also some experts on the Antique Roses forum that can help if it is an older variety. At first I thought it might be Dortmund, a Kordes climber, but the petals look too short. Beautiful photos, by the way.