Great Plains solid stand

Recently purchased a Great Plains solid stand 15 with center pivot hitch. It's an 89 model. I know the older models such as this are quite set up like the newer models. Any recommendations on add-ons or set up? It only has 2400 acres on it but I'm going through replacing all bushings on the row units as well as coulter spring bushings. I have heard to add weight to the caddy. 1000-1500 lbs. either use weights or water filled tanks. I just want to upgrade what I can on it to make it efficient.

Great Plains solid stand