As a neo-natal Pitts pilot, I will read anything that is I feel may either contribute to my safety or longevity, hence following this thread...
I have just finished Fred DeLacerda's book Surviving Spins (ISBN 0-8138-0142-7).
His C150 research is based on 105 one-turn spins and 42 multi-turn spins totalling 281 turns using two different airframes.
In it he discusses the Muller-Beggs recovery technique but his research shows that the no-hands recovery will not work after 3 turns for A C150. He does go on to say that that it may work again after 5 but that piece of work was still outstanding, this was because of rotation rates stabilising.
He concludes the chapter by stating that the C150 is very predictable and will recover as advertised "PROVIDED the airplane is maintained and flown within manufacturer recommendations."
Nothing new there then.
Apparently Cessna in 1980 published a booklet
Spin Characteristics of Cessna Models 150,, A150, A152, 172, A172, & 177.
sNr