After turning my head and looking at the 2nd pic side ways, I agree w/SandDawg, it's the PTO lever
A few words of caution and an FYI.
1st off the T030 is a very good tractor. It's got plenty of power and can lift well over 1000lbs at the 3ph. The fact it was free makes it outstanding and it's well worth whatever it'l take to mae it 100% servicable.
This tractor does not have "live power" meaning the 3PH will not operate unless the pto is engaged and running (that lever in your 2nd pic

). Also when you step on the clutch to either stop or shift gears it also disengages the PTO, meaning theres no hydraulic power being applied to the 3PH. Generally the 3ph will stay up for a little while with the clutch disengaged but it's not unusual for it to start dropping alittle within sec's, alot depend on the weight on it. It also depends on how much wear is in the 3PH cylinder. Rebuild kits are readily available if needed.
If you plan on operating a 5' rotary cutter or finish mower you absolutely need to have a PTO overrunning clutch adaptor on the pto shaft. If it doesn't have one you can pick one up at TSC or any other tractor supply place for around $30. It slides on the end of the PTO shaft and you drive a pin in it to keep it on.
The reason you want one of these is because the PTO shaft is mechanically connected to the rear drive axles through the tranny. Not directly but connected all the same.
Lets say you are brush-hogging along a fence row and you push in the clutch to either downshift or slow down inorder to turn, well the centrifical force of the spinning rotary cutter will still continue to drive the rear wheels for a foot or two or three and theres been many the story of farmers being driven through fences because of this. The overrunning clutch adapter stops this.
Remember, depressing the clutch disengages the engine from the tranny, NOT the pto from the rear wheels.
Another thing. lets say you want to transport that rotary cutter and you either want to lift it and carry it high or just carry it low and only lift it when you encounter an obstacle, in either case you have to have the pto engaged inorder for the 3PH to lift and guess what that also does, it'll spin the mower up too. Most folks don't want their mower running in transport mode so what I did (and most everyone else) was to make a large loop of wire ( I used electric fencing but a rope or similar will work), and I hung that loop through the 3PH top link to where it hung down about 8" or 9" and I'd then disconnect the mowers driveshaft from the PTO overrunning clutch adapter and hang it in this loop. It was high enough to where it wouldn't hit or interfere w/the spinning pto shaft. Now I could transport the mower with the lift working and the pto spinning without the mower itself running.
Theres alot more info & tricks that I'm sure others will update you on. Congrats on getting such a nice tractor fir such a really good price
Dave