Well the core was sorted so the the next stage.
The cylinders running along the top and bottom were ordinary 2 inch bore plastic pipes,
the kinda thing used for low pressure plumbing and gutter down pipes.

I made up a master cap end with the detail then moulded and cast enough to cap all the pipes on the model.
The smaller red colour tubes with the detail on were made from a single master,
designed so that when assembled they could be rotated so that different detail
parts could be seen before painting and placing on the model.

At a glance they have the appearance of being different when in fact they are identical.
16 needed to be cast for the job.