Right the details I have on the loco are this:- she was No 850 and she was the only GSR Prairie that they had, there is photo in the GSR Loco book which turned up last week, it is reported that she wore the CIE Green livery up until she was scraped, that said the front cover of the GSR Locomotive book has a painting of her in the grey livery.
She was the only one in her class (P1) Tractive Effort 17,700lbs, she was built in 1928 and withdrawn in 1955.
The 1948 assessment said of her that she was quite powerful but needed a lot of repairs, but she could not be replaced.
She worked manly over the DSER Section, also there was much unconfirmed speculation that she used up all the spare Woolwich components, but it was highly unlikely this was the case, as she would not have been able to run since she would have had an axle loading of over the maximum of 19 tons per axle for the DSER.
From the details I have she was a marmite loco some people loved her and others didn't.
She was supposed to be the first of three locos, but I guess that teething troubles which where reported from the crews halted the building of other members of the class.
you can find more details about her on page 265 in the GSR locomotive book by colourpoint.
She makes for a really good model
Colin