Beautiful model, and well painted!
The GSWR took over the WLWR, though, a couple of years after they replaced their WLWR maroon with GSWR (pre-grey!) lined black, so no ex-WLWR loco would have ever carried GSWR green.
However, as the model shows, GSWR green would have suited them well.
291 & 293 of that class, somewhat bizarrely, were regulars on the Loughrea branch from the 1930s to early 50s….