I had it in my mind that GWR locos bound for Bournemouth did not work past Salisbury until late steam days?
Robert Waterman comments "As it is a 43xx a possible explanation is that it had come from Weymouth (or in this this case is going back to Weymouth). I believe they sometimes did. I certainly remember seeing one pass through Poole on an up freight, admittedly in 1961 though. "