Howdy and WELCOME to the Forum from the East Side!
Perfectly okay for you to make such posts seeking information and identification.
For some reason we all love looking at pictures of steam engines and such!?!?
Certainly not a Jensen, and also not at all common. I think Dave's guess is pretty close to the mark!
Somewhere on the side of the firebox or even in the pressure gauge face there may be some embossed markings that could help tell the tale?!?!