Thanks Zathros, I used the formers as per Zosho's design. I was poking around on the "other" forum and found a design that is 1:1000 scale (modified Zosho). This one is big, but that will be huge! basic eyeball comparison of the design puts this one at about 1:2000.
Progress has been delayed a bit, I moved into my own place over the Easter weekend, had to leave the model stuff at my parents for now. I'm doing bit by bit, currently working on the lighting for the saucer