1976 mercedes benz 300d

for sale a 1976 mercedes benz 300 d i bought it not running i did get it running but it has a engine knock and doesnt run well .It wont rev up very fast i think its somthing to do with the throttle linkage .It has a new battery and a new brake master cylinder. Im not sure if the transmission works it does go into drive and reverse but with it not going much faster than idle its hard to tell if its going to work ok .I pulled up the carpet and there is some rust holes in the floor pan in front of the back seats .The seats look very good for the cars age .There are still a lot of lines under the hood that need replacedThis is a project so it cant be driven yet .