The WW&F #9 was mentioned above and it is getting a new boiler. Partly because it is lap seam and no longer legal to run.

Second, the project will create a new forward frame from I think the B&SR 6 which was also a Portland locomotive.

This will allow it to pass a FRA inspection in case the museum ever decides to go under their governance.
Basicly you can not use the boiler as the frame for the locomotive as the #9 does now.

Ted Miles

This FEA image shows the re-designed forward frame area Ted is referring to for No 9. This was done to remove the boiler as an integral part of the frame -- which it had always been. Ted is correct in that the design is borrowed from later Portland Co. locomotive building practice.

Image by Josh Botting