Hey Mike, looks like ya got a #4 or #5 there...(stanley's nominclature) it would be #9 were it a miller falls...Look on the blade/frog and chipbreaker for some kinda name or info. If there is no name stamped on it anywhere, chances are its an off brand. That isn't to say it won't be a good plane for ya. She looks like she might clean up real well for you. The tote and handle look solid.. thats a good thing. The sole needs to be perfectly flat and true...the mouth opening is very inportant as well and should be square to the blade.
Very cool to have a tool with a lil family history behind it...*S*