This 1972 book is available on Amazon, Abe Books, and Ebay right now (Oct. 2023) An Amazon review says:
The fascinating story of special friendships between McGredy, Poulsen and Kordes. Articles about rose hybridizing, marketing and sales, told by Sam McGredy in personal entertaining style.
Printed with nice old fashioned letters and black and white pencil drawings. Color pictures can be found on:
Help Me Find and Just Our Pictures Roses.
Excerpt:
One evening Pat Dickson and I joined the Kordes family in their living-room, drinking from a bowl of champagne and peaches. It wasn't long before we were all singing Lilli Marleen. I suggested that the new red rose should be called by this name, and it was agreed there and then.