It depends what direction you want to go with it. If you want to marry the crested roses with modern hybrids that have good color, its going to be a long road indeed. The problem is that the cresting trait is lost very quickly in breeding. To keep significant cresting in hybrids, you will need to backcross to previous hybrids and siblings to enhance the trait. Most of the best work has come out of ‘Crested Jewel’ (‘Little Darling’ X ‘Chapeau de Napoleon’) in part because it was the most fertile hybrid of the Moore crested roses. However, very few of the seedlings from it have cresting, and often it is diminished. You may gain repeat bloom but will lose most or all of the cresting trait, and so back to Crested Jewel you must go again. Lather, rinse, and repeat about 8 or 10 generations and you will eventually have your crested golden Yellow rose!
Now, this is not to say that it isn’t possible, because Ralph Moore did make significant progress in this area. However, he would be the first to tell you that to get really good crested roses in good colors with generous repeat would take a good 20 years or more. Myself, I have pretty much given up the quest, at least for now. I did several years work in this area and I have little to show for it. The best thing I ever got came from Marbree X Crested Jewel and was named Crested Damask. (see link below) I had a hunch the cresting trait had a greater affinity for the old European roses than modern remontant shrubs and that is why I made the cross. I have seen Crested Damask occasionally produce seed hips, but I’ve never had one germinate. Very little else of note ever came out of my work with the crested roses, but…
If I were to resume this line of breeding I would absolutely go back to Crested Jewel again. I have one seedling I kept that came from a sowing of open pollinated Crested Jewel seed about 7 years ago. It looks almost identical to Crested Jewel in bloom and in cresting, but it repeats about 3 times in the growing season. I’ve never used it in breeding, but perhaps I should.
The other seedling I have came directly out of Chapeau de Napoleon. It is Nightmoss X Chapeau de Napoleon, and it has the remarkable trait of showing both normal mossing AND cresting on the buds. It is a weak shrub, and once blooming only, and the blooms are only 12 petals and a rather dull lavender, but its a unique rose with the mossed, crested sepals. Since it doesn’t likely have any of the remontancy genes left in it, I never pursued it as a breeder.
By all means, have a go at this line of breeding, just be aware that you are looking at many generations of work and you will be frustrated along the way by sterility issues, and the difficulty of keeping the traits you want the most.
If you have any other questions I can answer, I’ll be glad to do my best.