Dragonfly Ship - engine extra

Had a good rummage and came up with these wheel bits from a 1/35th Tamiya tank, which fit nicely onto the end of the test tubes.
The original plan was to have the tubes surrounding an whacking great engine bell, but i found this clear green piece - part of the Ker-Plunk game (bought for its plastic straws, a recommendation from Martin Bower for girder work).
Its the same diameter as the body and i figure it could finish off the dragonfly look for the craft, being a sting-like affair.
That raises the question of what to do for an engine bell but figure whatever is chucked out by the engine now will be coming out the nozzles of the tubes.
You can see i've made a couple of Plasticard pipes to slid over the body to enable the tubes to be glued on all the way round.