My father-in-law gave me this 8 foot tine harrow. It is VERY heavy with a lot of moving parts which obviously are not moving right now. The harrow has independent right and left sides connected by several links. I’m thinking this is for uneven ground. You can see the chains from one side to the other or not even and I have to straighten that out. I guess they are for sway control. I would like to know anything about this harrow make and age, and get any advice on how to loosen up the tine bars so they move freely which I’m not sure why but it appears to be by design.