If the rosebush is still there, have you considered making a cutting of it and rooting it? It would be a multi-year project to turn it into another rosebush, but I bet it could be done. The book "The 20 Minute Gardener" has a fun section about sneaking into graveyards to take cuttings of rosebushes to get easy-care varieties that you can grow yourself, including detailed instructions for how to root a rosebush cutting.