Just a follow up on this thread. First, just to let everyone know, Deutz-Fahr is back in the US bigtime! I finally called their Georgia office, and found that over the last year or two, they have already added over 70 dealers across the US. They connected me with a new dealer in central NY only an hour away. I called, and they had all the parts books for my Same Solaris 35. I can basically order any part that they still have in stock with no problems. So anyone with one of the Same (or Hurliman, etc.) tractors, the Deutz dealers are available and all around the US.
Now for the overheating issue. My tractor has had the fan changed at some point to pull air through the radiator, rather than push it. I ordered the original "push" type fan, since I thought I would go back to stock as a starting point. However, I forgot to order the spacer, so when I removed the fan the new one wouldn't go on properly. However, the one on the tractor was professionally done, with a machined aluminum space. It was a very heavy duty unit, and with only 200 hours on the tractor, I assumed it was done by a dealer. So I reinstalled it until I get the proper space. There is an open mesh metal safety screen around the fan, and it occurred to me that without a proper shroud it wouldn't pull much air through the radiator. So I used aluminum duct tape to tape over the mesh and create a shroud. Not the prettiest in the world, but effective.
With the improvised shroud and pull type fan, under heavy load (a 72" finish mower in heavy grass) it would run hot, but not overheat into the red. Then I did an experiment, and removed the side panels as posted above. Viola! No overheating! I am amazed, but the side panels really raised the engine temp. So as long as I leave the side panels off, it seems there is no overheating issue.
All this points to an inadequate radiator, since everything is running marginally and these small changes are enough to make it overheat or not. So at the end of the season, I am probably going to get the radiator recored with some extra capacity. There is about an inch of extra space I could use with a thicker core. I really like the tractor overall, so I don't mind fussing with it a bit and try to eliminate the root cause of the overheating.
It is odd to me though, how the tractor made it out of the design phase an into the real world with it obviously overheating in stock condition. Surely somebody at Same noticed it would overheat under heavy usage and that removing the side panels would help.