You have a 1020 there. They are rated ten tons lifting and 3/4 yard as dragline/shovel/hoe/etc. The left lever is the swing/travel/boom hoist, middle is lower drum, and the right lever (which you apear to be missing, your machine must only have one drum? but it still has brakes for two drums?) would be hoist. The tall lever off to the front right is the swing/travel/boom selector, the small one with the lock to the right of it is the steering lever. The small lever on the right that swivels is the swing lock, make sure you have it disingaged when you put the machine in swing and try to swing it, or you can rip the lock right off the machine. I am suspecting that your machine also has a torque converter because I don't see the master clutch lever, but there is a pedal in it's place (guess you could have a master clutch peadel, but ive never seen that before :beatsme). Does it have the Detroit 3-71 engine or a gas engine? The old Units were a tough, quick, dependable crane, and most of the clutches/brakes are interchangeable, not only on the machine, but between most models.
Landlasher - I would say that the Unit in your pictures is a 5 or 6 Ton (half yard) model 514 or 614 - due to the smooth counterweight.
We just serviced our 1965 Unit 1220 this weekend and got it ready for another season. My grandpa has always had a Unit crane or excavator, or both, or several of both around here since the 50s so I guess I've picked up a little bit about them. If you have any other questions ask away.
Heres a picture of our old girl