Slightly off topic, but if you like Terriers and 0 gauge, it is worth considering the coarse-scale alternative to the models under discussion here.
They are made by ETS in the Czech Republic on behalf of two UK suppliers, both with websites, Raylo and W J Vintage, and are switchable 2/3 rail.
These are "modern tinplate" models, all metal, with a very sophisticated clutch/motor system that runs silky-smooth. Price is about the same as Dapol, and liveries are manifold, including KESR, GWR and LSWR AR, as well as various Brighton, SR and BR ones.
Picture is of my LSWR one, hauling modern tinplate stock from Darstaed and Ace.
Kevin