You've got fireblight! Either the bacteria was in the scion wood but more likely it over-wintered in your golden delicious tree. The way you can find out is by cutting branches on the golden delicious - if the cut turns orange within 24-48h it's definitely fireblight. Golden Delicious is definitely prone to fireblight, see http://www.ext.colostate.edu/pubs/Garden/02907.html. I'd cut the grafts off and try to control the infection in the tree, the ooze will spread the disease to your other trees via insects that feed on the ooze - perhaps the tree is already infected into the roots, in which case you need to replace it. I've grafted as late as May and June and never had any issue, so it's not the graft timing.

How deeply were the roses planted? Is there a possibility that they were planted deeply enough for the scion to have developed its own roots? If so, your OGRs could live on indefinitely, especially if they are well-tended on a regular basis. I don't know if there are differences in longevity among the various root stocks, but I do know that roses remaining dependent on a grafted rootstock can live for decades. I'm presently a member of a neighborhood group that is tending a garden of 'modern' roses, a number of which we know were planted by the 92-yr-old owner in the early 1950's. Many of the roses are obviously well past their prime -- others, however, remain amazingly robust and productive. I think that life expectancy of roses in general depends on the specific variety, the quality of care received over time, and whether a given rose is grown under climatic conditions that meet its basic needs.

different-species grafting is a NO NO GOD is gonna get you for that!! ;o) You have to graft within a species like apple to apple. However I did once manage to graft an apple onto pear tree up north after what seemed like a thousand tries. Lou

That looks like an achlorophyllus Gymnocalycium grafted on to a non-tropical cactus. The new growth was chimeric. Parts of the chimera reverted to achlorophyllus Gymno. I'm not sure how that much of the achlorophyllus Gymno. grew. I don't grow them. However, now I kinda want to try making a chimeric cactus.