Hold your fire!!
The system was converted two years ago by a certified AC shop using a new (not rebuilt) Nippondenso compressor and new dryer. The pressure hose was replaced, as it was the source of the leak. It worked well even in the 100+f / 99% humidity summers of south GA. Not as fast, but well enough. I had to break the system when the engine was pulled due to a rounded Allen head bolt on the fuel cooler. I am simply recharging what is an already converted system. I have had good results converting other vehicles just blowing half a can of R134 through the system, adding ester and recharging. My 89 Honda for example. Converted five years ago and still cools well enough to suit me. My Toyota truck was converted in 98 and works well too. "Cooling well" is a subjective term. The only way to measure a system is the temp of the output air and I can live with 40 degrees. My Honda will go to 35. Both those vehicles are "disposable" so great if they work, so what if they don't. This MB is another story. I don't want to have to buy another Nippondenso!!
So, with that said, I should charge to around 200 on the high side? That sounds high. And, pressure may be pressure, but the scales read differently for each gas.