Mercedes W123 Airfilter Rubber Pipe

[pixelsblack009]

Hi, Recently we had our AC done up and the guy stole the rubber pipe/tip of the air filter housing would anyone know what its called or could anyone provide me with a part number?

PS: our AC seems to be having some kind of gas leak, it had just been gassed and it didn't last even 3 months there is no cool air, and the AC compressor does not hold any load, earlier when its on idle and the AC is turned on you could hear a little RPM drop. AC compressor clutch is working.
Any common problems?

Its been some time since I'd been here

Thanks Jeremy