advise please

I bought a 1995 chevy 4x4 with 57,000 miles last month in Ohio. The truck is in really good shape and the miles are relatively low. I looked the vehicle over and seemed to be solid. I soon found an oil leak which they said was the oil filter adapter. "Common problem" to the dealership. They agreed to fix it. Oil was still leaking and was determined to be the rear main seal. The dealer agreed to fix it also. Next, I noticed a slight leak on the top end of the motor. I thought it was the valve cover gasket. The dealer stated that it was up to me to fix. I agreed and replaced the gasket. That was not the problem. It ended up being the intake gasket, a 200.00 job. The shop that repaired the intake says a front axel seal needs replacing since it is also leaking fluids.
When I spoke to the salesman initially, he stated that all of their used cars go through their service dept. to ensure that they are mechanically correct. I feel that he misrepresented the vehicle since alot of defects were not brought to light in their so called "safety check". Do I have a case??