Hello dear oldtimer friends, I have an Opel record 2.0 E, built in 1983. I would have the following concerns about this car: The refrigerant of the air conditioning system in record has been out for a long time due to a small leak. The leak is not a problem to find, but the refrigerant R12, which would be the right remedy for this air conditioning system, has been banned for a long time in Austria and Germany or in general in the EU. Replacement refrigerants (e.g. R437A). My questions are: Which is the best replacement refrigerant for the R12? Can you just use this replacement refrigerant instead of the R12, or do you still have to pay attention to various special features (seals etc.)? How much of the replacement refrigerant do I need to refill my air conditioner? Thank you in advance for your answers. LG Didi