Hello, some time ago I have created a bunch of alternative instruments for Nebulae V1 in Pure data:
3OP FM
Oscillator build of three stacked FM operators, 3rd modulating 2nd, 2nd modulating 1st (basically a half of the 3rd DX7 algorithm)
Link: Nebulae_3OP_FM
4SimpleDrums
Simple four-part drum generator
Link: Nebulae_4SimpleDrums
Chord
Stack of four oscillators with continuously variable waveshapes and with selectable harmonic relations
Link: Nebulae_Chord
DrDrum
One-part drum generator capable of storing and editing 4 presets (resets after power off)
Link: Nebulae_DrDrum
Dual Osc
Dual oscillator with continuously variable waveshape + low pass filter
Link: Nebulae_Dual_Osc
Feel free to check them out and let me know what you think! 
They should work on Nebulae V2 as well after little adjustments. Unfortunately I don’t have V2 to test them.