seats for 1979 450 SL
 

I can't seem to get the seats in this car to slide on their tracks. The quy I bought the car from says that he replaced the original seats with seats he had gotten from a sedan and that sedan seats are slightly wider, so they don't clear the tunnel between the seats. This isn't immediately obvious looking at the seats so I wanted to check the accuracy of the information before I either spent a lot of time and effort getting the seats to slide, or started looking for new seats.

Any other suggested approaches to resolving this problem would also be appreciated.

Thanks