Raymond;
This is VERY nice! I doubted that the name was correct because the plant is so huge and neither parent is as big! So, I had a look at the Mont Cambrai pictured on PhragWeb and other than the petals being a bit shorter, the flower has the exact colouring and markings as your flowers. Then, I looked at Mary Bess and it's shocking how different they look. So, it does seem to be named correctly and it has simply been cultivated to perfection! Well done!
I'm very impressed with your culture of this plant. Would you please share how you grow it? You've done a fine job and I'd like to learn something new. What is your water source. What fertilizer do you use and at what strength and how often. Potting mix? pH adjustment? Anything that you can tell us would be VERY much appreciated!
Thanks!
John