3 1/2 inch gauge LMS Black 5

The engine runs on air after a fashion in reverse, not forwards.

It's evidently been steamed in the past and, at 80psi the boiler shows no sign of leaks - however the omission of six stays in the backhead deviates from the design (and put us off steaming it ourselves!).

Not a particularly difficult job to fit the missing stays, although the boiler will need to come off the frames to do it.