I hope you left some of the stem behind on the mother bush. Keep track of this stem, and it should send out new branches with the same mutation. Propagate it by vegetative means - either by layering or cutting, search threads by George Mander, Cheryl Netter, and object16. Because this is a mutation, you own the proprietary rights to this rose, and
you can give it your own name. Sativa.

wow! sounds like a find of a lifetime! I suggest the same and later when the sport(mutation) branch gets large enough take a few cuttings and root them or try grafting a bud onto a rootstock, or both!