There are a couple of groups where info may be found
The Model Fireboat Website! - Home Page! firefloat : Firefloat RAF Crash Tender
boath have info that may help you and may get you thinking a bit more about getting it out there is also a fireboat fun day in september, there is info on the first link . there are a lot of people building/restoring these boats and there are plenty of fittings avalable, there is also quite a lot of information avalable that was proberley not around when you built yours
Peter