Dear Cass,
I was unable to find any mention of 'Doorenbos Selection' but I did come up with
Sam McGredy's address at the 1971 International Rose Convention in Hamilton New Zealand wherein he said:

At the other end of the scale we want roses with no heps for one of the most important types of roses they raise are varieties for parks. This is entirely different to breeding roses for the home garden and in Europe in particular there is a vast market and a nursery may expect orders for fifteen thousand to twenty thousand roses of one variety from a local authority for planting in their areas, not only in parks but on traffic roundabouts and so on. What they require are far different from what the ordinary rose society member wants. For example, though he obviously would not breed for this, they do not care about the shape of the bloom; One of the most successful in Holland is 'Anneke Doorenbos', an impossible name and an absolutely impossible flower. Every bloom quarters and there is absolutely no shape, but it is one of the most popular roses in Holland, for it is so plain and so very healthy.