Help! Steam engine oilers

I need help! My father has 2 Automatic oilers for steam engines that he would like to sell. We really have no idea what he has or what they are worth. I can not find similar pictures online. All I can really say is they have 6 ports(?) The reservoir is app 7" high and teh whole piece is app 24" high. I do have 1 pic attached here. Any information on what it is or maybe even where I can find more info on it and where to sell it would be great. Thanks in advance for your help!