If you had used all "1"s in your custom model, then you could set the Start Channel to 150.
Then you could also Copy each model, changing the Start Channels to 153 and 156 and 159, but the base model would remain the same.
Alternately, if you left the current model filled with "150" you could just increment the Start Channel by 3 for your copies. Second set would be 4, then 7, then 10