That's a real beauty Nick, and I do love Fleischmanns as a quality engine from the "old" school.
I actually have one in similar condition, perhaps not quite as nice as yours, that I also believe to be unfired, or maybe only nearly so. It still has its original box and literature as well, though the box is rather out of shape but still structurally okay. I'll have to dig mine back out to confirm what I've said, but I think it is correct. I think mine has a blue base, though I may be confusing it with another as I have three.