Proper freon charge for a 85 300 SD?

It is a W126 chassis. There is a sticker on the top front /radiator, but it lists THREE different charges, the average of the first two is about 2.5 lbs, the last is much higher. It's funny it is not in Kg, being a German
car. I assume the different charges are for different production runs, but I couldn't decipher it.. I also need to know what normal low side pressure should be. Thanks, Jim

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