*Update* Maybe I can turn this thread in the direction of fixing this winch problem with or without seller's help. I greatly appreciate all who have given advice and hope to learn more. I was able to remove the cover without taking the bumper off. It looks like there is no damage other than the cracked case, bent cover, and some rust. It appears that the cover indeed is shaped with that dimple and it was not caused by catastrophic failure. Peering inside the filler hole/vent, there is a channel that obstructs the view into the drive. There is some oil visible, which I am pleased to find. So, the troubleshooting continues in a different direction. I am now leaning towards a possible hydro pump or control problem. The pay in/out switch in the cab operates correctly, as the valve up front can be seen to go up and down when the switch is thrown. So maybe the activation switch in the cab, OR perhaps I am so lucky that the hydraulic filter is so clogged that no fluid can pass through it. Next, I will be trying to find a replacement filter and hoping for more insightful help from you all. (incidentally, I loosed the band a full turn in accordance with advice given)