Thanks guys.
Having made four main engine casings...

...I decided I needed some detail thingy to go on the top, an intake of some description would be cool. So I thought I would make one...and then three more.
The first one did not work as well as I hoped, but the second version was much better.

I cut the middle out of a display base and then made a load of turbine blades.

I am happy enough with the finished article and will make three more.
I still need four more old paint lids for rocket nozzles before these get finished.