Hmm... This tree is interesting for two facts.
First your photos do not show any white selfs. Are there any? If not it’s what I think is called a Jiai sport. With white self’s it might be Gettoku....
The second reason it is interesting is the ruffled flowers that show up in cultivars like Gumpo. This means to me it is an older cultivar or a new jiai sport of an older cultivar as ruffled flowers were popular from the 1920‘s to the 1950’s and became virtually non existent after that In the new cultivars. But jiai colors are in vogue today. So I checked the 2020 Satsuki Dictionary and couldn’t find any hits for new jiai sports. Then I dug out the dusty old 1997 Satsuki Dictionary and came up with a Kuruijishi Satsuki.. a cultivar I hadn’t run across before, that looks similar to the photos posted by OP.
Here is a not great image of an image of a Kuruijishi satsuki azalea. Sadly it was shot with a red background! The blotches, the sectors, color patterns and ruffles all match. So yes 96.9% confidence.
So far that’s what I came up with. It’s not optimal in that I couldn’t find Kuruijishi for sale, but that’s a common issue Satsuki wide.
However, If there are white selfs, it’s an entirely different story, starting with Gettoku.
I hope that helps.
cheers
DSD sends