Hi,as far as your tie rods go its always good to get a second opinion from another shop. They need to be replaced if there is play or loosness in the joint when you shake the wheel back and forth while it is on the lift. On your master make sure your replacements are not new/remanufactured,they have a higher failure rate than new because they only repace seals whith standard size after honing the bore. One other thing to make sure is that they are flushing all the old fluid out because brake fluid absorbs moisture as it ages which can cause corrision in your hydralic system. And on your gas tank I am familure with the 67/68 and they have a rubber hose connecting the filler tube to the tank with hose clamps so if yours is the same maybe its somthing easy to check/repair, maybe one of the 69 members can chime in. As far as gas tank repair kits go I did a temporary fix on a 4x4 woods truck that ended up lasting 4 years until I sold it! I made the repair on a flat clean surface not on a seam though. Good luck.