The old bilge pumps in the engine rooms were also partly cleaned up. Now you can see through the grub and grime, it turns out they are a thing of beauty.
The top bits are bronze and need cleaning off, likely in a sand chamber. Rather conveniently rumour is toby the welder has just bought one of these.
One of the tops is missing but the remaining four are marked up with initials. There is a prize for anyone who knows what these stand for… Answers below!
betaiiifireboat 
ER =engine room
FP=forward peak
AC=aft cabin
TR =tank room
Excellent. I knew someone would have an idea!
Takes me back to proper old ships. The bronze bilge valve manifold was very common and a very elegant way of sucking the bilges out from different compartments. The pipe on the right of the pic with the sight glass should go to the bilge pump suction and by opening the relevant valve wheel to the space concerned will suck out the bilge contents. The missing valve wheel probably had AP =Aft Peak stamped on it.