I thought I would make this announcement easier to find, as a lot of people seem to have not worked it out yet.
It transpired today that Model Rail, in cooperation with Rapido Trains, is to be producing the GWR Class 1600 0-6-0PT, which will be available in the following versions:
1648 BR Black early
1627 BR Black early (weathered)
1646 BR Black early
1624 BR Black late
1636 BR Black late (weathered)
1638 GWR Green (as preserved)
I will post more details when I can!