Marty Nee’s article in the latest LPS Journal [1] introduced a stamp variant not listed by Scott (essentially Scott #O22 with "ORDINARY" overprinted rather than handstamped). Prompted by his comment that most catalogues also do not list this—only Stanley Gibbons shows it, having included it through Philip Cockrill’s review of Liberia listings for their specialised 1981 West Africa catalogue [2]—I too took a look around.
Sure enough, I see that some other, less-common catalogues similarly do not list this variant, all likewise listing only on the handstamped "OS" version: Kohl's (1912), anyone? Or Froede (1942), or Minkus (1964)?
Michel goes further, however. A modern Michel catalogue [3] also does not list the overprinted variant, and lists only the handstamped "OS" on the 32¢ stamp (Michel #66): “MiNr. 60-62 und 66 Handdruckstempel-Aufdruck.”
It is one thing not to list a stamp, however; it is a whole extra step to state outright that it does not exist.
An older Michel edition (1924) goes as far as to state confidently, in so many words, that there was no 32¢ on which the "OS" was printed: "Nr. 66 (32 C.) nur im Handstempelaufdruck erschienen (s. Nr. 66 H)." (That is: "No. 66 (32 C.) only appeared as a handstamp overprint (see No. 66 H).").
[1] Martin Nee, “No Ordinary Stamp”, LPS Journal, The Journal of the Liberian Philatelic Society, 9(4), (October - December 2026), 21-22
[2] Stanley Gibbons Stamp Catalogue, Part 13, Africa Since Independence, F-M, First Edition, 1981, (London: Stanley Gibbons Publications Ltd; 1981), pp87-88
[3] Michel Übersee 2019, Band 5.2: Westafrika (H-Z), (Gemering: Schwaneberger Verlag GmbH; 2019), 125
[4] Hugo Michel's Briefmarken-Katalog 1924 II. Teil: Übersee, (Leipzig: Verlag des Schwaneberger Album Schaufuss & Stolpe G.M.b.H: 1924), 254.