What do mean by a blue model Nick? Mine looks just like the one on the left, blue base but with the brass boiler.
My description wasn't the best, I'll see if I can find a picture... from memory, it had a "smoke effect" base with blue trim/engine base, likely made some time between my 2 models.
As soon as you said smoked base I knew just what you mean't and your picture confirmed it. I've seen those before but it's been a long time.
It's like nobody wants to get rid of them. You'll find one, and then another, and another and, well you know how this goes.