J. W. Bowker 2-4-0? Don't think the slope back tender came with the Bowker, but it does look like a starting point for a cool old time switcher.
HO Scale Could this be one of the AHM Mini-trains HOn2½ gauge engines? HMMMMMMM http://tycotrain.tripod.com/ahmhoscaletrainscollectorsresource/id85.html
I don't think it is a Bowker. The Bowker model has molded 'equipment' between the drivers, while this model has some kind of brass piece. The cab side is different too. The Bowker has one cab side panel with trim around the nameplate, while this model has four small panels. Is this a diecast or plastic model? That may narrow it down. Edit: I just found it. It is a diecast Aristo-Craft model. From what I have seen, it is CBQ 335. I don't know if they made other road numbers.