The comments below assume it's the original fork and frame, which I think it is.
From my list above, since 50158 is a 1942, I guess that 44324 is a March 41, with the 3 double stamped (31)
There no combination of 133 makes sense, (133, 313, 331). If the 3 is double stamped, we have a choice of 31 (March 41) and 13 (Jan 43). But it can't be Jan 43, because the serial number is too low, and the bicycle shows no blackout features.
Incidentally, looking at the list, the first bike number (19471) is a little suspicious. I will check my reference on this this week, but it could be 49471, with a badly stamped 4 looking like a 1 at the start. It would make more sense.