Don, There is a fine-cut chopper attachment for either the 62 or 72. It replaces the impeller that normally helps to exhaust the straw after it leaves the rotor. I installed one on my R72. It's not a big job, but it's not trivial either. I think it took us a couple days. It does a good job of chopping the straw and I'm glad I added it to my machine.

Biggest difference between the 62 and 72 is the engine. The 98 R62 runs an 8.3 Cummins set @ 260HP. The 98 R72 runs an M11 Cummins set at 330 HP. The R72 has a 330 bu. bin as standard. R62 was around 285 -- I think??? There was a running change during the model year, that installed shock absorbers on the feeder chain front drum. Should be added if it isn't all ready there.

Looks like the heads on the machines pictured is the 700 model. Nice big auger with deep flighting feeds evenly. In picture1 on your link, it looks like the left shield in front of the unload auger is crinkled. Possibly the after effects of either the hydro belt or bin unload belt failing? Hard to tell if the machines have the fine-cut installed when the left shield is down. If it has a chopper, there will be a large (14" or so dia.) that drives the chopper. If it only has the impeller, it will have a much smaller drive sheave.