Where do you fill power steering fluid in a 1973 450sl Mercedes and do you use transmission fluid you cannot find the reservoir thank you?

The resivoir is a small black tank about the size of a soup can. It sets above the powr steering belt and has a silver screw which hods the cover in place. Take the screw off and lift the cover to add fluid. Use Transmission Fluid only.

The resivoir is a small black tank about the size of a soup can. It sets above the powr steering belt and has a silver screw which hods the cover in place. Take the screw off and lift the cover to add fluid. Use transmission fluid only.