Like the sandboxes the front and rear tanks are cast in whitemetal.
These are glued under the front of the chassis.
There is the risk of a "short" here because the tanks are very close to the metal rail under the bufferbeam. Fortunately they don't quite touch, and in any case only one of the tanks is in electrical contact with the chassis (by chance the other has been isolated by the epoxy).
I suppose the small hole on the front of the tank can be used to secure the pipework from the front bufferbeam, but connecting this would make it difficult to remove the chassis. One to think about.
rear tanks (smaller one goes on right side)
The pegs fit in holes on the outside frame. I had to open the holes to get these to fit.
rear cylinder etch and castings
The etch folds around the casting.
On some locos these appear quite prominently situated directly under the back bufferbeam, but in several photos of my prototype I can't identify them. So for now I'll leave them off.