Need help identifying
The engine is a Stuart Double 10. The boiler looks a bit dodgy, have it hydraulics tested and checked over before steaming. Brong it to working pressure in increments, ie take up to 10 psi, cool, take to 20 psi and so on until you reach working pressure. Look for numbers stamped into the boiler, usually around the burner tube, there numbers will be needed for a test certificate. The hull looks free lance...
If it don't fit, use a hammer to make it fit....