Does anyone know what kind of suspension this is on the front wheel?
It looks like something that could be home made with relative ease (I'm guessing!).
Has anyone else attempted to use suspension like this or similar?
That's a Raleigh or Mobylette (most Raleighs were Mobylettes under licence). It's a leading link type fork with rubber in tension as the springing medium. I never saw one that didn't look saggy and tired. And would you trust your life to a biodegradable spring? Tension springs would be ok if you could sort out the damping.
No, I certainly wouldn't! I had assumed there was a piece of bendy metal or even a steel spring hidden under that mudguard, I'd never have guessed it was rubber.
Perhaps something similar could be made using steel springs?
Big Boy Cycles use an elastomer material on their bikes suspension.
I haven't ridden one yet, but they seem to work very well on the
street and the track.