Thanks @JonnyUK, I had an early finish today so have been tinkering.
It is supposedly quite lightweight, and I’ve only got ex-heli batteries so I am thinking of doubling up to add some mass. I reckon I can fit them pannier style to lower the CoG at the expense of some front end weight bias.
The main thing I’ve noticed today is the ball joints on the shocks are distorted, which limits the movement available so I’ll get some alloy ones to cure that.
Bike suspension grease has helped free the shocks up, as has completely filling the shocks when assembling them, they suck down slightly now so they sit further into the travel and that’s helped.
Thanks again for the reply, and my springs shall stay as they are! 🙂