I can confirm that this is correct - 153329 to be precise - ruuning 14 minutes late. This would mean that that the 0811 Weymouth Gt Malvern (not good as this is often an extremely busy train), 1251 Gt Malvern Weymouth (1449 ex Bristol TM‡) and 1711 Weymouth Cheltenham will be so formed. Interestingly, a 150 and a 158 were noted stabled in the sidings at Westbury this morning.
If it was a Ex-Arriva 150 you saw, then it formed the 07:38 to Great Malvern from Westbury. Interestingly it arrived 150+158 from Warminster and also joined onto the 143 pacer I boarded down to Westbury this morning, to form a
FGW▸ 143+ ex
ATW▸ 150+ ex TPX 158 6 car combo Great Malvern train. A real mix up, but 6 cars will be appriciated by passengers further up the line. I took a video of this on my phone, see the link below!! (apologies for the quality, anyone with a Sony Ericsson phone will know what the video quality is like!)
http://www.youtube.com/watch?v=odDLPyG_7KQ