Standard Guide to Razors, 3rd Ed. book...

Just picked up the book at an antique store this weekend...gotta say, there's just not much to the book that I haven't picked up here. There's some nice color pics in it though. The book seems to lean more to the scale collectors than anything else and the 'pricing algorithm' that is presented seems kinda arbitrary and doesn't reflect real life. Their method of calculating value puts WAY too much emphasis on the scales rather than the razor being honed, NOS, or shave ready.

I suppose what I was expecting was something along the lines of a list of marks, dates of production, and perhaps a short history of the maker...I know there's a book out there for this, but does anybody have any good leads for me?