Dodge got cold, true story
We had a 1991 Dodge Spirit that came with R12 when we bought it in 91. Through the years the A/C became slowly less efficient and finally the clutch on the A/C stopped engaging (low refrigerant caused this I thought). It was dead for a couple of years.
In 2003 I put a WalMart $30 R134a kit in it on the driveway. I did nothing else, no testing (except with the guage included in kit), no fixing, no O-rings, no drier, no evacuating, nothing else. That A/C blew nice cold air again and still did when I sold it this spring.
A bit of caution:
This was an old car, not very valuable.
Nobody was going to pay anybody a cent to get the A/C working again, therefore there was nothing to lose.