I've flicked through the sample of African Ripples and I'm sorry to say these transcriptions are inaccurate with poor chord voicings. Even considering any `tidying up' (it's a matter of opinion which `wrong notes' should be omitted) it's not good. Pick a page at random - Page 10 - last bar of the second line, both chords incorrect in right hand, missing an E and B flat respectively, the left hand on beat 3 is not what's happening, anyone can hear the lowest note hit is a D. 6 bars later on beat 3 there's a low D missing. And so on. If the point of this book is to see literally what Fats Waller plays then don't waste your money and encourage authors who present shoddy work and get paid for it. I'm a composer with a good ear and what I'm saying is a fact. Why Dick Hyman endorsed it I do not know. It's competently edited in terms of rubato, speed etc. but anyone musician could do that.
The average standard of accuracy in published jazz piano transcriptions seems to be very poor, e.g. Erroll Garner or Artis Wodehouses' woeful attempts at Gershwin's 1920s recordings. When transcribing you must play back each chord until you can literally hear every note one by one in reality and know which notes are not harmonics. It's not rocket science, it just needs a lot of time and care and attention to every detail.