I agree with Bronto. For instance, that M60 is really rough. When I was in an M60A3 platoon, our tanks were fully repainted several times a year. When I was on M1A1 and M1A2 tanks with the 1st Cav, they were repainted so frequently I truly couldn't keep track throughout the course of a year.
Likewise with the M110 road wheel; that leakage is considered a Class 1 leak. The military classifies leaks as Class 1, 2 or 3. Class 1 is the presence of moisture and it would be noted on the daily maintenance log (DA Form 2404) and would be monitored and repaired at the next service or probably more quickly if it developed into a Class 2 leak.
A Class 2 leak is when the fluid begins to form a drop when the vehicle sits for any length of time. That would be repaired as soon as possible, like at the next maintenance halt or when it got back to the motor pool.
A Class 3 leak is basically dripping or spewing of the fluids. It would be remedied immediately if possible.
The dinged up road wheels could be in multiple stages of disrepair. The rear ones tended to get more cracks than the front ones because of the rubbing of the center guides created vibrations in the metal that eventually would cause the separation of the rubber from the metal. A forward road wheel probably wasn't replaced as often as the rear so it would appear more beat up and "chunked" than the rear ones.
In active duty service, a tank probably had its track replaced annually. We used to road march along the autobahn from Grafenwohr to Hohenfels (a 3 hour tour, a 3 hour tour). It took its toll on the tracks and road wheels just because of the heat and vibrations. A National Guard tank of the same make may sit for years without moving more than a mile. We also tracked vehicle usage by miles AND hours. The engines ran constantly without the vehicles moving during gunnery, alerts, maintenance, etc.
The National Guard also kept a couple of tanks at their armory that stayed there. When they went on their two week annual training, they drew vehicles from a motor pool (MATES site or USAR ECS site) at whatever fort or camp they went to. Since they are using "rent-a-tanks", they don't treat them as well as they would vehicles the crew was permanently assigned to.
Much like the photos I took when I ran the maintenance school at Fort Devens, the details are good, but don't look too much into the weathering. My vehicles sat until needed for a class. Other than the recovery vehicles, the tactical vehicles didn't have a lot of operational wear and tear from being in the field or having men live on them. They did have a lot of wear from having engines removed, components replaced, and sitting on concrete in the sun, rain, snow and ice.