Mitsubishi may still be making their paper: http://www.mitsubishiimaging.com/color-paper.html
Yes they are and so are at least 2 Chinese companies, and various other no name brands, or non branded generic stuff.
Having just read J39, i would say its better to follow the manual then random numbers recalled of someones memory.
While RA4 is very forgiving, the chart calls for 35 degrees C, in the case of rotation processing in a tube, such as a Jobo.
You have a CPP2, and can set and adjust the temperature down to 0.1C degrees, and i would suggest following the charts and doing just that.
100F is 37.7C, sometimes used as a simple way to explain to non C users the processing temperature of C41 and E-6 (38.4C), in some case that might be close enough, though as far as i can read J39, has nothing to do with any RA4 processing option they discuss.