Does the fuel drip when the car is running? I would think the vacuum during operation could only leak air to the intake.
I wonder where the slop is. Perhaps damage is confined to the threads of the needle screw, which means only the needle needs to be replaced. I've actually made needles by finding the right size screw and sharpening the tip. The screw is clamped in a drill chuck and ground on a grinding wheel, while operating the drill.
Or perhaps there's a compound like loctite that can be put on the threads to take up the gap, yet allow for adjustment.
95 E320 Cabriolet, 131K