As regular readers will be aware, what I know about boats can be written on the thin edge of a sail. I'm on slightly firmer ground with this one as there's a steam engine inside it.
Starting with the bits I understand, somebody has done rather a nice job of building a Stuart Double Ten and gearing it to a pair of propellors, there's a displacement lubricator and a centre-flue water tube boiler with pressurised blowlamp type burner. It's pretty grubby but underneath it's nicely made and tidily plumbed up.
The boat bit is a disaster, the hull itself looks just about seaworthy, the superstructure on top looks as if it's been through a mangle. "Complete rebuild" springs to mind.
Stowed away below decks is some electronicy-looking stuff - might be the remains of some control system, alternatively a prop from "Quatermass".
Length 50 inches