First, I would check to see if you can put mild pressure on the tank using the line from the needle valve and the line from the muffler (Block one and put a bulb on the other). That will tell you if there is a cracked or broken line or a crack in the tank. Make sure that you have the correct line going to the muffler and to the needle valve. Was the tank drained and clean before you put the Senior away? If it had some old manky oil in it from last decade's fuel, I would expect strange results. The vibration might just be an out of balance prop, or residue of old fuel in the tank. I would make sure that you get good fuel delivery first. Glow plugs can look good but have a few contaminated coils that make the motor run poorly...this is not unusual in breaking in new motors, but this sounds like fuel delivery issues to me.