It all depends on attachments at the time of sale (new or dealer modified). It shows palletless so it had either a slip sheet, appliance grab, paper roll or other attachment plus possibly sideshift. All of this along with lift height and tilt angle will affect the center of gravity thus the rated load. I can't read much of it. Contact your local Clark dealer and give them the complete model and serial number. They "may" get a line sheet for you. The line sheet will tell you what it was built from and the special parts. This should tell you all the info that you need. Because of the age, getting the tilt to the correct angle will require the dealer contacting engineering and getting the correct dimensions for the angle stops. The reason for this is, when you have a fairly high lift height the tilt will be restricted to keep it inside the safety envelope. If you don't care about tilt angle just ignore this part.
