Wonder if it's case sensitive - code checks for "FET"...
Yours looks quite strange - it generated values over 255, weird. I've done a lot of them, experimenting, etc. This is one example below. I always use .BAT files so i can capture the exact command line options:
rem for FET+1, 124 levels 4X LED's
level_calc.py 2 124 7135 3 0.3 160 FET 1 10 5000
PWM1 values: 3,3,4,4,5,6,8,9,11,13,15,18,21,25,28,33,37,43,48,55,61,69,77,85,94,
104,115,126,138,151,164,178,193,209,226,243,255,255,255,255,255,255,255,255,255,
255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,
255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,
255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,
255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,0
PWM2 values: 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
,0,0,1,1,2,3,3,4,5,6,7,8,9,10,11,12,13,14,15,17,18,19,21,22,23,25,27,28,30,31,33
,35,37,39,41,43,45,47,49,52,54,56,59,61,64,66,69,72,75,78,80,83,87,90,93,96,100,
103,107,110,114,117,121,125,129,133,137,141,146,150,154,159,164,168,173,178,183,
188,193,198,203,209,214,220,225,231,237,243,249,255