Justin McNamara as George/kitten swing is most likely the grey boy beside Alonzo on the right of the front row.
Matthew Jackson as Carbucketty/tall swing is likely the one on the top right, between Sillabub and chorus Deut.
The Chorus Deut is most likely David Outtrim the chorus/Deut & Gus u/s.
Michael Larsen-Disney (Chorus) will be one of the Plato and Macavity, as he covered that role.Danielle Goullet and Makeely Louise Clarke were both Etcetera (presumably only one on per show). The main Etcetera costumes seems to be the one on the right, diagonally up from Mungojerrie and under Sillabub. This costume can be seen on the right of this pictures, at the back, visible between Mistoffelees and Sillabub. George is also visible on the left, behind Skimble.
The other is probably the bottom left of the main picture, looking like Jellylorum Junior.