UPDATE:
I had a lot of this system sorted out, or so I thought. There have been a few adjustments, instead of mounting the diaphragm pump in the cavity beside the tank, I moved it to under the drivers seat. I did this because it was easier to
mount, I also put a tap on it to drain out the water mix through the floor when I need to make room for ice.
I mounted a shaped block of balsa wood to create a platform for the base of the pump to sit. The base plate has rubber grommets to isolate vibration, but I also mounted a soft sanding block to it to really knock back vibration.
The hoses help keep it in place, but I cut a piece of used valve cover gasket, put some bolts in the gasket holes to stop it tearing and screwed it across the motor to be safe.
I had a slight weeping issue with the tank due to taking out the wire stitching, so I gave it another lick of flowcoat and am doing a filled water test overnight to make sure it's all good.
I made a dash switch taking a spare demist switch and putting a hazard cover on it so I could fit it in the same place as the other switches and keep the OEM look.
The light from the demist switch works when switched on too. :thumbsup: It's wired in with accessories so it can be turned on with the engine off to help pump out the heatsoak if I've parked it for a bit.
It is not too bad as far as volume goes, diaphragm pumps are normally loud as, but this one's not much different to a fuel pump.