The numbers after the date are the number of transmissions assembled that day in this case 0036 is the 36th assembled at the PP new process. Normally there are another set of numbers above these and those are the vin identifiers. This could have been, and probably is, a warranty case as it was never stamped with vin.
PP = New process plant
833 = Transmission type
3394 = Day 3394 is Thursday, November 12, 1970 (1971 model year of assembly)
0036 = 36th transmission assembled to yours
c-99129 - typical case number, the throwout bearing retainer number will give front bearing size. This could be small 307 or large 308 front bearing.
c-99126 = 1969-71 A-body transmissions w/30 spline output shaft and 307 bearing.