Like Rod's, my older Scott omits only P15-24, as well as P35, adding that "counterfeit overprints comprise most of the examples offered for sale in the marketplace."
The reason for the apparently growing list of omissions could be something similar to what Scott says about P2-9. Those had, it seems, a different "Imprimé" overprint, but Scott says many examples were "prepared on private order" and P2-9 therefore "have no official status as newspaper stamps."
For the overprint shown in Floortrader's post, my copy of Michel (also not the most recent) lists five values for 1891: the same that Scott lists as P10-14. The same for 1892: P25-9. Michel adds the same warning about counterfeits and unauthorized, in fact "illegal," overprints of this type.
For more info Michel suggests P.E. Engler's essay in Türkei-Speigel 2 & 3 (1988), as well as the October 1988 edition of Arbeitsgemeinschaft Osmanisches Reich/Türkei (AROS). http://arosturk.org/aos.htm
( And good luck with that! )