I got a semi grunt and nod of half approval from SWMBO, so I will step tentatively into the project. I think having it on castors is the main factor that may mean I will get away with it! I have realised that its going to be tight getting it through the door if I need to remove it - something I just need to keep in mind (I already have a cunning plan, just means a redesign of the trolley).
As for the finish, I have found a stockist of the West system close to me - it seems to be only marginally more expensive the Fibreglass resin, so I think I will use that.
Off to the hardware store in the morning!