p.313 : "To date no documentation has been uncovered that list the exact time that any meetings took place, but it can be assumed sometime in year 1933 the principle manufacturers of the region met with Heer representatives to map out a strategy to produce a Carbine version of the Kar 98b rifle".
Looking at the Mauser document on page 168 about "Vorführungsprogramm vor dem Heern Chef des Heereswaffenamts" dated 16 October 1933, an additional speculation would be that these meetings happened earlier than October 1933.
Production of the not-yet-adopted 98k started during late 1934 at Mauser (p.197) and early to middle of 1934 at J.P Sauer & Sohn (p.316).
Assuming a 1 year "meeting to start-up" period, meetings of Thuringian manufacturers with Heer officials might have happened early to middle of 1933 (Hitler becomes a Chancellor on 30 January).
p.314 and 316: I guess contract 7/6875/33 of 14,500 carbines is nowhere to be found. Too bad!
p.317: the Luftwaffe drilling is such a ludicrous survival rifle !
p.329: "the OKH retained ownership of the machinery involved in production": Vorsprung durch Sozialismus
p.335: "Note that while J.P. Sauer isn't the cheapest manufacturer the rejection rate is lowest of all barrel manufacturers" [report of 1942, rejection rate of 4.2%]
p.359: the "navy blue" blueing of this S/147 1937 is truly beautiful !