I owned a 1970 model 350 Case about 15 years ago. Good little machine if you are doing light work and small jobs. Not good for pushing over large trees or digging out well roote stumps.
Make sure you get one with good undercarriage or get one at a price where you can afford to put good undercarriage on it.
I also recommend a 6-way blade.
As others have said, these are relatively easy and inexpensive to work on.