Ah the main engine bells, caused me a few headaches.

I didn't have a lathe capable of turning them out and getting a set made
after enquiring was going to cost about 200 plus,
never mind the takeoff/landing engine bells.

So in traditional manner I improvised with some nuts and bolts,
some old ball race bearings,
one big lump of solid urethane resin and a pillar drill.

Ended up with a kind of upright lathe,
crude I know but did the job enough to turn out
one solid engine bell.
Some years later I found out it wasn't exactly
correct but too late by then.

The bell was moulded and then the mould was laid up with a thin
coating of resin then an inner plug poured.
Two part mould done and items turned out.
Sorted and onward.