From the photo's they appear to be Glencoe's made in Illinois. They are very simple inexpensive cylinders and used an O ring seal so are made for low pressure of the Gresen pump. It is probably a vane style pump and operated at about 1000 psi max. They cylinder is so large that the load would move before the pressure ever developed very high so you good.
Unfortunately Glencoe no longer makes hoists and may not even be in business any longer. Do a Google on them for farm implements and the like.
The barrels were not chromed so I'd just go after then with emory cloth as previously suggested and clean them up if not pitted to badly. Hope this info is of some value to you.
