That is a MB910 top, MB903 middle (not sure on number) and a MB920 bottom. Supposedly they are the best built matco boxes of their time back in the day.
I have that bottom box with a 26" wide matco box sitting on top. It is very rugged, I like the thin drawers. They are all friction slide drawers, the bottom most drawer on the bottom box had dual friction slides. If it is in good condition, I guess $600 wouldn't be bad, but from the blury pics, to me it looks a bit rough. They are nice boxes but unless you really like that style, I wouldn't go crazy paying for a worn out set. Yes, they are 33" wide, x 18" deep x ~68+" tall.
EDIT, here are a few pics I saved thanks to members on here. Inspiration we will call it. I love the blue color, but the red looks sharp as well. Hopefully those members won't mind, if so let me know and I will take the pics down.
