Boy I wish I found things like that at Garage Sales!
I have a Steam pump from the same Manufacturer. The only difference mine is a bit (alot) bigger than that one.
Unfortunately I don't have any good photos of my pump with me at the moment. Will see if I get a chance over the next couple of days. However my pump looks identical to a typical duplex weir pump.
It does mention that it is a Blake Knowles made in New York Boston just like your example. I haven't found out much about mine yet. All I know so far there aren't many around (that I have seen) and that Blake Knowles did change there name a couple of times.