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.
Satsuki have so many cultivars that look superficially similar. It is pointless speculating what it MIGHT be because 'might be' also means it might not be too.
Without a definitive ID it is just a Satsuki azalea.
Grow it because it is lovely and don't worry about a cultivar name.
You could almost say 'An azalea by any other name would look as good' (doesn't quite work as well as Bill's version)
Closest cultivar seems to be Asahizuru. It has no whites, clear pinks, and speckled light pinks, all ruffled petals. The book photo shows the deeper pinks to be a bit deeper and salmon-colored than yours, but I suspect it’s the photo (and the photo of the photo).
@Deep Sea Diver There do not appear to be any white selfs. I do know that this was an import about 20 years ago if that is a clue...I do not have this tree until next week in my hands, and who knows if its actually flowering when I get it. So once I see how close a match the flowers are to these photos, I'll post again. I know it doesn't really matter, and I'm really just OCD about knowing what it is, but it's nice to hunt for a match. Thanks @Brian Van Fleet and @Pitoon and Deep Sea Diver for taking a look for me! @Shibui I will enjoy it no matter what!