[JasonB]

I've held back till now as I realise I'm not really qualified to read this thread...

Could someone briefly explain slush casting to me?

Slush casting is when you have just a mould of the outside of a body, and you pour in resin and swirl it around until it sets, to build up the wall thickness.

As opposed to having a two part mould for the inside and outside, which is obviously a more reliable way to define the wall thicknesses, but it's more complicated to make the moulds.